Hydrogenated amorphous carbon(a-C:H)films are capable of providing excellent superlubricating properties,which have great potential serving as self-lubricating protective layer for mechanical systems in extreme workin...Hydrogenated amorphous carbon(a-C:H)films are capable of providing excellent superlubricating properties,which have great potential serving as self-lubricating protective layer for mechanical systems in extreme working conditions.However,it is still a huge challenge to develop a-C:H films capable of achieving robust superlubricity state in vacuum.The main obstacle derives from the lack of knowledge on the influencing mechanism of deposition parameters on the films bonding structure and its relation to their self-lubrication performance.Aiming at finding the optimized deposition energy and revealing its influencing mechanism on superlubricity,a series of highly-hydrogenated a-C:H films were synthesized with appropriate ion energy,and systematic tribological experiments and structural characterization were conducted.The results highlight the pivotal role of ion energy on film composition,nanoclustering structure,and bonding state,which determine mechanical properties of highly-hydrogenated a-C:H films and surface passivation ability and hence their superlubricity performance in vacuum.The optimized superlubricity performance with the lowest friction coefficient of 0.006 coupled with the lowest wear rate emerges when the carbon ion energy is just beyond the penetration threshold of subplantation.The combined growth process of surface chemisorption and subsurface implantation is the key for a-C:H films to acquire stiff nanoclustering network and high volume of hydrogen incorporation,which enables a robust near-frictionless sliding surface.These findings can provide a guidance towards a more effective manipulation of self-lubricating a-C:H films for space application.展开更多
To realize the application of electromagnetic wave absorption(EWA)devices in humid marine environments,bifunctional EWA materials with better EWA capacities and anticorrosion properties have great exploration signific...To realize the application of electromagnetic wave absorption(EWA)devices in humid marine environments,bifunctional EWA materials with better EWA capacities and anticorrosion properties have great exploration significance and systematic research re-quirements.By utilizing the low-cost and excellent magnetic and stable chemical characteristics of barium ferrite(BaFe_(12)O_(19))and using the high dielectric loss and excellent chemical inertia of nanocarbon clusters,a new type of nanocomposites with carbon nanoclusters en-capsulating BaFe_(12)O_(19)was designed and synthesized by combining an impregnation method and a high-temperature calcination strategy.Furthermore,Ce-Mn ions were introduced into the BaFe_(12)O_(19)lattice to improve the dielectric and magnetic properties of BaFe_(12)O_(19)cores significantly,and the energy band structure of the doped lattice and the orders of Ce replacing Fe sites were calculated.Benefiting from Ce-Mn ion doping and carbon nanocluster encapsulation,the composite material exhibited excellent dual functionality of corrosion resist-ance and EWA.When BaCe_(0.2)Mn_(0.3)Fe_(11.5)O_(19)-C(BCM-C)was calcined at 600°C,the minimum reflection loss of-20.1 dB was achieved at 14.43 GHz.The Ku band’s effective absorption bandwidth of 4.25 GHz was achieved at an absorber thickness of only 1.3 mm.The BCM-C/polydimethylsiloxane coating had excellent corrosion resistance in the simulated marine environment(3.5wt%NaCl solution).The|Z|0.01Hz value of BCM-C remained at 106Ω·cm^(2)after 12 soaking days.The successful preparation of the BaFe_(12)O_(19)composite en-capsulated with carbon nanoclusters provides new insights into the preparation of multifunctional absorbent materials and the fabrication of absorbent devices applied in humid marine environments in the future.展开更多
Remarkable progress has characterized the field of electrocatalysis in recent decades,driven in part by an enhanced comprehension of catalyst structures and mechanisms at the nanoscale.Atomically precise metal nanoclu...Remarkable progress has characterized the field of electrocatalysis in recent decades,driven in part by an enhanced comprehension of catalyst structures and mechanisms at the nanoscale.Atomically precise metal nanoclusters,serving as exemplary models,significantly expand the range of accessible structures through diverse cores and ligands,creating an exceptional platform for the investigation of catalytic reactions.Notably,ligand‐protected Au nanoclusters(NCs)with precisely defined core numbers offer a distinct advantage in elucidating the correlation between their specific structures and the reaction mechanisms in electrocatalysis.The strategic modulation of the fine microstructures of Au NCs presents crucial opportunities for tailoring their electrocatalytic performance across various reactions.This review delves into the profound structural effects of Au NC cores and ligands in electrocatalysis,elucidating their underlying mechanisms.A detailed exploration of the fundamentals of Au NCs,considering core and ligand structures,follows.Subsequently,the interaction between the core and ligand structures of Au NCs and their impact on electrocatalytic performance in diverse reactions are examined.Concluding the discourse,challenges and personal prospects are presented to guide the rational design of efficient electrocatalysts and advance electrocatalytic reactions.展开更多
On the basis of coordinated electrodeposition of carboxylated chitosan(CCS),we presented a green method to prepare Cu NCs and Cu NCs/CCS nanocomposite films.The method shows a range of benefits,such as the convenient ...On the basis of coordinated electrodeposition of carboxylated chitosan(CCS),we presented a green method to prepare Cu NCs and Cu NCs/CCS nanocomposite films.The method shows a range of benefits,such as the convenient and eco-friendly process,mild conditions,and simple post-treatment.The experimental results reveal that a homogeneous deposited film(Cu NCs/CCS nanocomposite film)is generated on the Cu plate(the anode)after electrodeposition,which exhibits an obvious red florescence.The results from TEM observation suggest there are nanoparticles(with the average particle size of 2.3 nm)in the deposited film.Spectral analysis results both demonstrate the existence of Cu NCs in the deposited film.Moreover,the Cu NCs/CCS film modified electrode is directly created through electrodeposition of CCS,which enables promising application in the electrochemical sensing.By means of fluorescence properties of Cu NCs,the Cu NCs/CCS film also owns the potential in fluorescence detection.Therefore,this work builds a novel method for the green synthesis of Cu NCs,meanwhile it offers a convenient and new electrodeposition strategy to prepare polysaccharide-based Cu NCs nanocomposites for uses in functional nanocomposites and bioelectronic devices.展开更多
Plasmon-induced hot-electron transfer from metal nanostructures is being intensely pursed in current photocatalytic research,however it remains elusive whether molecular-like metal clusters with excitonic behavior can...Plasmon-induced hot-electron transfer from metal nanostructures is being intensely pursed in current photocatalytic research,however it remains elusive whether molecular-like metal clusters with excitonic behavior can be used as light-harvesting materials in solar energy utilization such as photocatalytic methanol steam reforming.In this work,we report an atomically precise Cu_(13)cluster protected by dual ligands of thiolate and phosphine that can be viewed as the assembly of one top Cu atom and three Cu_(4)tetrahedra.The Cu_(13)H_(10)(SR)_(3)(PR’_(3))_(7)(SR=2,4-dichlorobenzenethiol,PR’_(3)=P(4-FC_(6)H_(4))_(3))cluster can give rise to highly efficient light-driven activity for methanol steam reforming toward H_(2)production.展开更多
The electrochemical carbon dioxide reduction reaction(eCO_(2)RR),which converts CO_(2)into various hydrocarbons or alcohols,has been extensively researched because it promises a sustainable energy economy.However,only...The electrochemical carbon dioxide reduction reaction(eCO_(2)RR),which converts CO_(2)into various hydrocarbons or alcohols,has been extensively researched because it promises a sustainable energy economy.However,only copper(Cu)can currently achieve stable and efficient hydrocarbon conversion in the eCO_(2)RR.Therefore,understanding the catalytic mechanisms and summarizing the research progress on synthesis strategies of Cu catalysts are essential for the eCO_(2)RR.This paper reviews Cu catalysts with different surface states of Cu catalysts:oxide-derived Cu,Cu nanoparticles,Cu single atoms,and Cu nanoclusters.It then reviews the development and progress of different Cu-catalyst preparation methods in recent years,focusing on the activity and selectivity of materials.Besides revealing the tendencies of catalytic selection and deep reactive mechanisms of Cu catalysts with four different surface states,this review can guide the subsequent construction of catalysts and provides an understanding of catalytic mechanisms.展开更多
Regulating the catalyst electronic structure is critical for improving the adsorption and catalytic conversion of lithium polysulfides(LiPSs)in lithium-sulfur batteries(Li-S),yet which has been overlooked in current s...Regulating the catalyst electronic structure is critical for improving the adsorption and catalytic conversion of lithium polysulfides(LiPSs)in lithium-sulfur batteries(Li-S),yet which has been overlooked in current studies.In this work,structurally defined Ag_(30)Pd_(4)nanoclusters were loaded onto reduced graphene oxide(Ag_(30)Pd_(4)/rGO)as a modification material for polypropylene(PP)separators to elucidate the catalytic activity towards lithium polysulfides and the impact on the electrochemical properties to lithium sulfur batteries.This unique d-πcombination promotes charge transfer,influences overall charge states,and further enhances adsorption energies in potential reaction pathways with lithium polysulfides.Consequently,the Ag_(30)Pd_(4)/rGO/PP modified batteries exhibited an exceptionally low-capacity decay rate of 0.026%per cycle at 1.0C over 1000 stable cycles and 9.75 mAh cm^(-2)excellent performance even with lean electrolyte and high sulfur loading(9.7 mg cm^(-2)).This study paves a path for employing ultrasmall bimetallic nanoclusters to promote the polysulfides redox kinetics hence boosting the lithiumsulfur battery performance.展开更多
Electrocatalytic CO_(2) reduction reaction (eCO_(2)RR) presents a promising approach for harnessing renewable energy and converting greenhouse gas (CO_(2)) into high value-added CO products.N-doped single atom (SA) an...Electrocatalytic CO_(2) reduction reaction (eCO_(2)RR) presents a promising approach for harnessing renewable energy and converting greenhouse gas (CO_(2)) into high value-added CO products.N-doped single atom (SA) and atomic-level metal nanocluster (MN) tandem catalysts with rich defects for eCO_(2)RR are reported,which achieved a maximum CO Faraday efficiency (FE_(CO)) of 97.7%(-0.7 V vs.RHE) in the H-type cell and maintained over 95% FE_(CO)at potentials from -0.18 to -0.73 V vs.RHE in the flow cell.Furthermore,the catalyst in the flow cell demonstrated a remarkably low onset potential of-0.14 V vs.RHE and the current density was approximately three times that of the H-type cell.Interestingly,XPS analysis indicates that carbon substrates containing defects have more pyridine-N content.DFT calculations and in-situ attenuated total reflection Fourier transform infrared support this finding by showing that the Ni-(N-C_(2))_(3) active sites with defect favors preferentially convert CO_(2)-to-CO.展开更多
Herein,we propose a simple and rapid approach for synthesizing a CuS/Ru composite that serves as a bifunctional electrocatalyst to promote hydrogen production and concurrently convert sulfion into a value-added sulfur...Herein,we propose a simple and rapid approach for synthesizing a CuS/Ru composite that serves as a bifunctional electrocatalyst to promote hydrogen production and concurrently convert sulfion into a value-added sulfur product.This composite comprises Ru nanoclusters supported on the CuS nanostructure,achieved through simple pulsed laser irradiation in liquid approach.The optimized CuS/Ru-30 electrocatalyst demonstrates remarkable bifunctional electrocatalytic activity,exhibiting a negligible working potential of 0.28 V(vs.RHE)for the anodic sulfion oxidation reaction(SOR)and a minimal overpotential of 182 m V for cathodic hydrogen evolution reaction(HER)to achieve 10 mA cm^(-2)of current density.Moreover,the Cu S/Ru-30 electrocatalyst shows exceptional selectivity for converting sulfion into valuable sulfur during anodic oxidation reactions.Remarkably,in a two-electrode electrolyzer system utilizing Cu S/Ru-30 as both the anode and cathode,the SOR+HER coupled water electrolysis system demands only 0.52 V to reach 10 mA cm^(-2),which is considerably lesser compared to the OER+HER coupled water electrolysis(1.85 V).The experimental results and density function theory(DFT)calculations reveal that the strong electron interaction between CuS and Ru nanoclusters generates a built-in electric field,greatly enhancing electron transfer efficiency.This significantly boosts the HER performance and facilitates the adsorption and production of sulfur intermediates.This study presents a rapid and simple strategy for synthesizing a dual-functional catalyst suitable for low-voltage hydrogen generation while facilitating the recovery of valuable sulfur sources.展开更多
The fragile antibody leads to a great challenge as a scaffold to fabricate the luminescent metal nanoclusters using one-pot method.This study presents a stable single-chain anti-body(scFv57R-ATS)for the fabrication of...The fragile antibody leads to a great challenge as a scaffold to fabricate the luminescent metal nanoclusters using one-pot method.This study presents a stable single-chain anti-body(scFv57R-ATS)for the fabrication of luminescent gold nanoclusters(AuNCs@scFv57R-ATS)and a quick,sensitive rabies virus detection in living cells.In this paper,AuNCs@scFv57R-ATS was designed to specifically recognize antigen RV in modified HeLa cells,which promoted the demonstration of metal nanocluster fluorescent probes for antigen targeting and therapy.展开更多
For the use of green hydrogen energy,it is crucial to have efficient photocatalytic activity for hydrogen generation by water reforming of methanol under mild conditions.Much attention has been paid to gC_(3)N_(4)as a...For the use of green hydrogen energy,it is crucial to have efficient photocatalytic activity for hydrogen generation by water reforming of methanol under mild conditions.Much attention has been paid to gC_(3)N_(4)as a promising photocatalyst for the generation of hydrogen.To improve the separation of photogenerated charge,porous nanosheet g-C_(3)N_(4)was modified with Pt nanoclusters(Pt/g-C_(3)N_(4))through impregnation and following photo-induced reduction.This catalyst showed excellent photocatalytic activity of water reforming of methanol fo r hydrogen production with a 17.12 mmol·g^(-1)·h^(-1)rate at room temperature,which was 311 times higher than that of the unmodified g-C_(3)N_(4).The strong interactions of Pt-N in Pt/g-C_(3)N_(4)constructed effective electron transfer channels to promote the separation of photogenerated electrons and holes effectively.In addition,in-situ infrared spectroscopy was used to investigate the intermediates of the hydrogen production reaction,which proved that methanol and water eventually turn into H_(2)and CO_(2)via formaldehyde and formate.This study provides insights for understanding the photocatalytic hydrogen production in the water reforming of methanol.展开更多
Photocatalytic oxygen(O_(2))reduction has been considered a promising method for hydrogen peroxide(H_(2)O_(2))production.However,the poor visible light harvesting and low-efficient separation and generation of charge ...Photocatalytic oxygen(O_(2))reduction has been considered a promising method for hydrogen peroxide(H_(2)O_(2))production.However,the poor visible light harvesting and low-efficient separation and generation of charge carriers of conventional photocatalysts strongly limited their photocatalytic H_(2)O_(2) generation performance.Herein,we design a highly efficient photocatalyst in this work by marrying luminescent gold-silver nanoclusters(AuAg NCs)to polyethyleneimine(PEI)modified C_(3)N_(4)(C3N4-PEI).The key design in this work is the utilization of highly luminescent AuAg NCs as photosensitizers to promote the generation and separation of charge carriers of C_(3)N_(4)-PEI,thereby ultimately producing abundant e−for O_(2) reduction under visible light illumination(λ≥400 nm).As a result,the as-designed photocatalyst(C3N4-PEI-AuAg NCs)exhibits excellent photocatalytic activity with an H_(2)O_(2) production capability of 82μM in pure water,which is 3.5 times higher than pristine C_(3)N_(4)(23μM).This interesting design provides a paradigm in developing other high-efficient photocatalysts for visible-light-driven H_(2)O_(2) production.展开更多
Water electrolysis via alkaline hydrogen evolution reaction(HER)is a promising approach for large-scale production of high-purity hydrogen at a low cost,utilizing renewable and clean energy.However,the sluggish kineti...Water electrolysis via alkaline hydrogen evolution reaction(HER)is a promising approach for large-scale production of high-purity hydrogen at a low cost,utilizing renewable and clean energy.However,the sluggish kinetics derived from the high energy barrier of water dissociation impedes seriously its practical application.Herein,a series of hybrid Pt nanoclusters/Ru nanowires(Pt/Ru NWs)catalysts are demonstrated to accelerate alkaline HER.And the optimized Pt/Ru NWs(10%wt Pt)exhibits exceptional performance with an ultralow overpotential(24 mV at 10 mA cm^(-2)),a small Tafel slope(26.3 mV dec^(-1)),and long-term stability,outperforming the benchmark commercial Pt/C-JM-20%wt catalyst.This amazing performance also occurred in the alkaline anion-exchange membrane water electrolysis devices,where it delivered a cell voltage of about 1.9 V at 1 A cm^(-2)and an outstanding stability(more than 100 h).The calculations have revealed such a superior performance exhibited by Pt/Ru NWs stems from the formed heterointerfaces,which significantly reduce the energy barrier of the decisive rate step of water dissociation via cooperative-action between Pt cluster and Ru substance.This work provides valuable perspectives for designing advanced materials toward alkaline HER and beyond.展开更多
The great promise of photodynamic therapy(PDT) has thrusted the rapid progress of developing highly effective photosensitizers(PS) in killing cancerous cells and bacteria. To mitigate the intrinsic limitations of the ...The great promise of photodynamic therapy(PDT) has thrusted the rapid progress of developing highly effective photosensitizers(PS) in killing cancerous cells and bacteria. To mitigate the intrinsic limitations of the classical molecular photosensitizers, researchers have been looking into designing new generation of nanomaterial-based photosensitizers(nano-photosensitizers) with better photostability and higher singlet oxygen generation(SOG) efficiency, and ways of enhancing the performance of existing photosensitizers. In this paper, we review the recent development of nano-photosensitizers and nanoplasmonic strategies to enhance the SOG efficiency for better PDT performance. Firstly, we explain the mechanism of reactive oxygen species generation by classical photosensitizers, followed by a brief discussion on the commercially available photosensitizers and their limitations in PDT. We then introduce three types of new generation nanophotosensitizers that can effectively produce singlet oxygen molecules under visible light illumination, i.e., aggregation-induced emission nanodots, metal nanoclusters (< 2 nm), and carbon dots. Different design approaches to synthesize these nano-photosensitizers were also discussed. To further enhance the SOG rate of nano-photosensitizers, plasmonic strategies on using different types of metal nanoparticles in both colloidal and planar metal-PS systems are reviewed. The key parameters that determine the metal-enhanced SOG(ME-SOG) efficiency and their underlined enhancement mechanism are discussed. Lastly, we highlight the future prospects of these nanoengineering strategies, and discuss how the future development in nanobiotechnology and theoretical simulation could accelerate the design of new photosensitizers and ME-SOG systems for highly effective image-guided photodynamic therapy.展开更多
Transition metal nitrides have attracted considerable attention as great potential anode materials due to their excellent metallic conductivity and high theoretical specific capacity.However,their cycling performance ...Transition metal nitrides have attracted considerable attention as great potential anode materials due to their excellent metallic conductivity and high theoretical specific capacity.However,their cycling performance is impeded by their instability caused by the reaction mechanism.Herein,we report the engineering and synthesis of a novel hybrid architecture composed of MoO2.0N0.5 atomic nanoclusters bonded in nanosheets of N-doped carbon hierarchical hollow microspheres(MoO2.0N0.5/NC)as an anode material for sodium-ion batteries.The facile self-templating strategy for the synthesis of MoO2.0N0.5/NC involves chemical polymerization and subsequent one-step calcination treatments.The design is benefi-cial to improve the electrochemical kinetics,buffer the volume variation of electrodes during cycling,and provide more interfacial active sites for sodium uptake.Due to these unique structural and compositional merits,these MoO2.0N0.5/NC exhibits excellent sodium storage performance in terms of superior rate capability and stable long cycle life.The work shows a feasible and effective way to design novel host candidates and solve the long-term cycling stability issues for sodium-ion batteries.展开更多
Exploring highly active but inexpensive electrocatalysts for the hydrogen evolution reaction(HER)is of critical importance for hydrogen production from electrochemical water splitting.Herein,we report a multicomponent...Exploring highly active but inexpensive electrocatalysts for the hydrogen evolution reaction(HER)is of critical importance for hydrogen production from electrochemical water splitting.Herein,we report a multicomponent catalyst with exceptional activity and durability for HER,in which cobalt nanoparticles were in-situ confined inside bamboo-like carbon nanotubes(CNTs)while ultralow ruthenium loading(~2.6μg per electrode area~cm^(−2))is uniformly deposited on their exterior walls(Co@CNTsǀRu).The atomic-scale structural investigations and theoretical calculations indicate that the confined inner Co and loaded outer Ru would induce charge redistribution and a synergistic electron coupling,not only optimizing the adsorption energy of H intermediates(ΔGH*)but also facilitating the electron/mass transfer.The as-developed Co@CNTsǀRu composite catalyst requires overpotentials of only 10,32,and 63 mV to afford a current density of 10 mA cm^(−2) in alkaline,acidic and neutral media,respectively,representing top-level catalytic activity among all reported HER catalysts.The current work may open a new insight into the rational design of carbon-supported metal catalysts for practical applications.展开更多
Selective reductive amination of carbonyl compounds with high activity is very essential for the chemical and pharmaceutical industry,but scarcely successful paradigm was reported via efficient photocatalytic reaction...Selective reductive amination of carbonyl compounds with high activity is very essential for the chemical and pharmaceutical industry,but scarcely successful paradigm was reported via efficient photocatalytic reactions.Herein,the ultrasmall Ru nanoclusters(~0.9 nm)were successfully fabricated over P25 support with positive charged Ru^(δ+)species at the interface.A new route was developed to achieve the furfural(FAL)to furfurylamine(FAM)by coupling the light-driven reductive amination and hydrogen transfer of ethanol over this type catalyst.Strikingly,the photocatalytic activity and selectivity are strongly dependent on the particle size and electronic structure of Ruthenium.The Ru^(δ+)species at the interface promote the formation of active imine intermediates;moreover,the Ru nanoclusters facilitate the separation efficiency of electrons and holes as well as accelerate the further hydrogenation of imine intermediates to product primary amines.In contrast Ru particles in larger nanometer size facilitate the formation of the furfuryl alcohol and excessive hydrogenation products.In addition,the coupling byproducts can be effectively inhibited via the construction of sub-nanocluster.This study offers a new path to produce the primary amines from biomass-derived carbonyl compounds over hybrid semiconductor/metal-clusters photocatalyst via light-driven tandem catalytic process.展开更多
The NO2 molecule adsorption on B12N12 nano-cage was investigated using density functional theory calculations in terms of adsorption energy, HOMO/LUMO energy gap （Eg） changes, charge transfer, structural deformation...The NO2 molecule adsorption on B12N12 nano-cage was investigated using density functional theory calculations in terms of adsorption energy, HOMO/LUMO energy gap （Eg） changes, charge transfer, structural deformation, etc. Furthermore, some aspects of stability and properties of B12N12 including calculation of binding electronic and Gibbs free energies, density of states, and molecular electrostatic potential surfaces are investigated. Three possible configurations for NO2 adsorption on the B12N12 nano-cage are energetically found. Interestingly, the results reveals that the Eg of B12N12 cluster is very sensitive to the pres- ence of NO2 molecules as its value reduces from 6.84 eV in free cluster to 3.23 eV in the most stable configuration of NO2/cluster complex. This phenomenon dramatically increases the electrical conductivity of the cluster, suggesting that the B12N12 nano-cluster may be potential sensor for NO2 gaseous molecule detection.展开更多
Singlet oxygen(1 O2) plays an important role in various applications, such as in the photodynamic therapy(PDT) of cancers,photodynamic inactivation of microorganisms, photo-degradation of toxic compounds, and photo-ox...Singlet oxygen(1 O2) plays an important role in various applications, such as in the photodynamic therapy(PDT) of cancers,photodynamic inactivation of microorganisms, photo-degradation of toxic compounds, and photo-oxidation in synthetic chemistry. Recently,water-soluble metal nanoclusters(NCs) have been utilized as photosensitizers for the generation of highly reactive 1 O2 because of their high water solubility, low toxicity, and surface functionalizability for targeted substances. In the case of metal NC-based photosensitizers, the photo-physical properties depend on the core size of the NCs and the core/ligand interfacial structures. A wide range of atomically precise gold NCs have been reported; however, reports on the synthesis of atomically precise silver NCs are limited due to the high reactivity and low photostability(i.e., easy oxidation) of Ag NCs. In addition, there have been few reports on what kinds of metal NCs can generate large amounts of 1 O2. In this study, we developed a new one-pot synthesis method of water-soluble Ag7(MBISA)6(MBISA= 2-mercapto-5-benzimidazolesulfonic acid sodium salt) NCs with highly efficient 1 O2 generation ability under the irradiation of white light emitting diodes(LEDs). The molecular formula and purity were determined by electrospray ionization mass spectrometry and gel electrophoresis. To the best of our knowledge, this is the first report on atomically precise thiolate silver clusters(Agn(SR)m) for efficient 1 O2 generation under visible light irradiation. The 1 O2 generation efficiency of Ag7(MBISA)6 NCs was higher than those of the following known water-soluble metal NCs: bovine serum albumin(BSA)-Au25 NCs,BSA-Ag8 NCs, BSA-Ag14 NCs,Ag25(dihydrolipoic acid)14 NCs,Ag35(glutathione)18 NCs,and Ag75(glutathione)40 NCs. The metal NCs examined in this study showed the following order of 1 O2 generation efficiency under white light irradiation: Ag7(MBISA)6 > BSA-Ag14 > Ag75(SG)40 > Ag35(SG)18 >BSA-Au25 >>BSA-Ags(not detected) and Ag2 s(DHLA)14(not detected). For further improving the 1 O2 generation of Ag7(MBISA)6 NCs, we developed a novel fluorescence resonance energy transfer(FRET) system by conjugating Ag7(MBISA)6 NCs with quinacrine(QC)(molar ratio of Ag NCs to QC is 1 : 0.5). We observed the FRET process,from QC to Ag7(MBISA)6 NCs,occurring in the conjugate. That is,the QC works as a donor chromophore,while the Ag NCs work as an acceptor chromophore in the FRET process. The FRET-mediated process caused a 2.3-fold increase in 1 O2 generation compared to that obtained with Ag7(MBISA)6 NCs alone. This study establishes a general and simple strategy for improving the PDT activity of metal NC-based photosensitizers.展开更多
The development of low-cost, earth-abundant and highly-efficient cocatalysts is still important to promote the photocatalytic H2 evolution reaction over semiconductors. Herein, a series of Ni nanoclusters（NCs） modif...The development of low-cost, earth-abundant and highly-efficient cocatalysts is still important to promote the photocatalytic H2 evolution reaction over semiconductors. Herein, a series of Ni nanoclusters（NCs） modified brookite TiO2 quasi nanocubes（BTN）（marked as Ni/BTN） are fabricated via a chemical reduction process. It is found that the loading content and oxidation state of Ni NCs can significantly influence the optical absorption, photocatalytic activity, and stability of Ni/BTN composites. Among the resultant Ni NCs-loaded products, 0.1%Ni/BTN composite delivers the best H2 evolution activity（156 μmol/h）,which is 4.3 times higher than that of the BTN alone（36 μmol/h）. Furthermore, the Ni NCs with ultrafine size（2 nm） and high dispersity enable shorter charge transfer distance by quickly capturing the photoexcited electrons of BTN, and thus result in the improved activity even though the oxidization of some Ni NCs on BTN is harmful to the activity for H2 evolution due to the much lower electron capturing capability of NiO than metallic Ni.This study not only clarifies that brookite TiO2 would be a promising high-efficient photocatalyst for H2 evolution, but also reveals vital clues for further improving its photocatalytic performance using low-cost Ni-based cocatalyst.展开更多
基金The authors would like to thank Dongzhou ZHAN for technological support during friction experiment.This work was supported by the National Natural Science Foundation of China(Nos.51925506,51975314,51935006,and 51527901).
文摘Hydrogenated amorphous carbon(a-C:H)films are capable of providing excellent superlubricating properties,which have great potential serving as self-lubricating protective layer for mechanical systems in extreme working conditions.However,it is still a huge challenge to develop a-C:H films capable of achieving robust superlubricity state in vacuum.The main obstacle derives from the lack of knowledge on the influencing mechanism of deposition parameters on the films bonding structure and its relation to their self-lubrication performance.Aiming at finding the optimized deposition energy and revealing its influencing mechanism on superlubricity,a series of highly-hydrogenated a-C:H films were synthesized with appropriate ion energy,and systematic tribological experiments and structural characterization were conducted.The results highlight the pivotal role of ion energy on film composition,nanoclustering structure,and bonding state,which determine mechanical properties of highly-hydrogenated a-C:H films and surface passivation ability and hence their superlubricity performance in vacuum.The optimized superlubricity performance with the lowest friction coefficient of 0.006 coupled with the lowest wear rate emerges when the carbon ion energy is just beyond the penetration threshold of subplantation.The combined growth process of surface chemisorption and subsurface implantation is the key for a-C:H films to acquire stiff nanoclustering network and high volume of hydrogen incorporation,which enables a robust near-frictionless sliding surface.These findings can provide a guidance towards a more effective manipulation of self-lubricating a-C:H films for space application.
基金supported by the National Key R&D Program of China(Nos.2022YFB3504804 and 2023YFF0718303)the National Natural Science Foundation of China(Nos.51871219,52071324,52031014,and 52401255)+1 种基金Science and Technology Project of Shenyang City(No.22-101-0-27)Liaoning Institute of Science and Technology Doctoral Initiation Fund Project(No.2307B19).
文摘To realize the application of electromagnetic wave absorption(EWA)devices in humid marine environments,bifunctional EWA materials with better EWA capacities and anticorrosion properties have great exploration significance and systematic research re-quirements.By utilizing the low-cost and excellent magnetic and stable chemical characteristics of barium ferrite(BaFe_(12)O_(19))and using the high dielectric loss and excellent chemical inertia of nanocarbon clusters,a new type of nanocomposites with carbon nanoclusters en-capsulating BaFe_(12)O_(19)was designed and synthesized by combining an impregnation method and a high-temperature calcination strategy.Furthermore,Ce-Mn ions were introduced into the BaFe_(12)O_(19)lattice to improve the dielectric and magnetic properties of BaFe_(12)O_(19)cores significantly,and the energy band structure of the doped lattice and the orders of Ce replacing Fe sites were calculated.Benefiting from Ce-Mn ion doping and carbon nanocluster encapsulation,the composite material exhibited excellent dual functionality of corrosion resist-ance and EWA.When BaCe_(0.2)Mn_(0.3)Fe_(11.5)O_(19)-C(BCM-C)was calcined at 600°C,the minimum reflection loss of-20.1 dB was achieved at 14.43 GHz.The Ku band’s effective absorption bandwidth of 4.25 GHz was achieved at an absorber thickness of only 1.3 mm.The BCM-C/polydimethylsiloxane coating had excellent corrosion resistance in the simulated marine environment(3.5wt%NaCl solution).The|Z|0.01Hz value of BCM-C remained at 106Ω·cm^(2)after 12 soaking days.The successful preparation of the BaFe_(12)O_(19)composite en-capsulated with carbon nanoclusters provides new insights into the preparation of multifunctional absorbent materials and the fabrication of absorbent devices applied in humid marine environments in the future.
基金Guangzhou Key R&D Program/Plan Unveiled Flagship Project,Grant/Award Number:20220602JBGS02Guangzhou Basic and Applied Basic Research Project,Grant/Award Number:202201011449+3 种基金Research Fund Program of Guangdong Provincial Key Laboratory of Fuel Cell Technology,Grant/Award Numbers:FC202220,FC202216Guangdong Basic and Applied Basic Research Foundation,Grant/Award Numbers:2021A1515010167,2022A1515011196National Natural Science Foundation of China,Grant/Award Numbers:21975292,21978331,22068008,52101186Training Program of the Major Research Plan of the National Natural Science Foundation of China,Grant/Award Number:92061124。
文摘Remarkable progress has characterized the field of electrocatalysis in recent decades,driven in part by an enhanced comprehension of catalyst structures and mechanisms at the nanoscale.Atomically precise metal nanoclusters,serving as exemplary models,significantly expand the range of accessible structures through diverse cores and ligands,creating an exceptional platform for the investigation of catalytic reactions.Notably,ligand‐protected Au nanoclusters(NCs)with precisely defined core numbers offer a distinct advantage in elucidating the correlation between their specific structures and the reaction mechanisms in electrocatalysis.The strategic modulation of the fine microstructures of Au NCs presents crucial opportunities for tailoring their electrocatalytic performance across various reactions.This review delves into the profound structural effects of Au NC cores and ligands in electrocatalysis,elucidating their underlying mechanisms.A detailed exploration of the fundamentals of Au NCs,considering core and ligand structures,follows.Subsequently,the interaction between the core and ligand structures of Au NCs and their impact on electrocatalytic performance in diverse reactions are examined.Concluding the discourse,challenges and personal prospects are presented to guide the rational design of efficient electrocatalysts and advance electrocatalytic reactions.
基金Funded by the National Natural Science Foundation of China(No.51873167)the Fundamental Research Funds for the Central Universities(WUT:2022-CL-A1-04)。
文摘On the basis of coordinated electrodeposition of carboxylated chitosan(CCS),we presented a green method to prepare Cu NCs and Cu NCs/CCS nanocomposite films.The method shows a range of benefits,such as the convenient and eco-friendly process,mild conditions,and simple post-treatment.The experimental results reveal that a homogeneous deposited film(Cu NCs/CCS nanocomposite film)is generated on the Cu plate(the anode)after electrodeposition,which exhibits an obvious red florescence.The results from TEM observation suggest there are nanoparticles(with the average particle size of 2.3 nm)in the deposited film.Spectral analysis results both demonstrate the existence of Cu NCs in the deposited film.Moreover,the Cu NCs/CCS film modified electrode is directly created through electrodeposition of CCS,which enables promising application in the electrochemical sensing.By means of fluorescence properties of Cu NCs,the Cu NCs/CCS film also owns the potential in fluorescence detection.Therefore,this work builds a novel method for the green synthesis of Cu NCs,meanwhile it offers a convenient and new electrodeposition strategy to prepare polysaccharide-based Cu NCs nanocomposites for uses in functional nanocomposites and bioelectronic devices.
基金financial support from National Natural Science Foundation of China(22125202,21932004,22101128)Natural Science Foundation of Jiangsu Province(BK20220033)。
文摘Plasmon-induced hot-electron transfer from metal nanostructures is being intensely pursed in current photocatalytic research,however it remains elusive whether molecular-like metal clusters with excitonic behavior can be used as light-harvesting materials in solar energy utilization such as photocatalytic methanol steam reforming.In this work,we report an atomically precise Cu_(13)cluster protected by dual ligands of thiolate and phosphine that can be viewed as the assembly of one top Cu atom and three Cu_(4)tetrahedra.The Cu_(13)H_(10)(SR)_(3)(PR’_(3))_(7)(SR=2,4-dichlorobenzenethiol,PR’_(3)=P(4-FC_(6)H_(4))_(3))cluster can give rise to highly efficient light-driven activity for methanol steam reforming toward H_(2)production.
基金supported by the Tianjin Science and Technology support key projects (20JCYBJC01420)。
文摘The electrochemical carbon dioxide reduction reaction(eCO_(2)RR),which converts CO_(2)into various hydrocarbons or alcohols,has been extensively researched because it promises a sustainable energy economy.However,only copper(Cu)can currently achieve stable and efficient hydrocarbon conversion in the eCO_(2)RR.Therefore,understanding the catalytic mechanisms and summarizing the research progress on synthesis strategies of Cu catalysts are essential for the eCO_(2)RR.This paper reviews Cu catalysts with different surface states of Cu catalysts:oxide-derived Cu,Cu nanoparticles,Cu single atoms,and Cu nanoclusters.It then reviews the development and progress of different Cu-catalyst preparation methods in recent years,focusing on the activity and selectivity of materials.Besides revealing the tendencies of catalytic selection and deep reactive mechanisms of Cu catalysts with four different surface states,this review can guide the subsequent construction of catalysts and provides an understanding of catalytic mechanisms.
基金supported in part by the Institute for Advanced Study of Central South University and the High Performance Computing Center of Central South Universitythe funding from Guangdong Natural Science Funds(No.2023A0505050107)。
文摘Regulating the catalyst electronic structure is critical for improving the adsorption and catalytic conversion of lithium polysulfides(LiPSs)in lithium-sulfur batteries(Li-S),yet which has been overlooked in current studies.In this work,structurally defined Ag_(30)Pd_(4)nanoclusters were loaded onto reduced graphene oxide(Ag_(30)Pd_(4)/rGO)as a modification material for polypropylene(PP)separators to elucidate the catalytic activity towards lithium polysulfides and the impact on the electrochemical properties to lithium sulfur batteries.This unique d-πcombination promotes charge transfer,influences overall charge states,and further enhances adsorption energies in potential reaction pathways with lithium polysulfides.Consequently,the Ag_(30)Pd_(4)/rGO/PP modified batteries exhibited an exceptionally low-capacity decay rate of 0.026%per cycle at 1.0C over 1000 stable cycles and 9.75 mAh cm^(-2)excellent performance even with lean electrolyte and high sulfur loading(9.7 mg cm^(-2)).This study paves a path for employing ultrasmall bimetallic nanoclusters to promote the polysulfides redox kinetics hence boosting the lithiumsulfur battery performance.
基金supported by the Tianjin Science and Technology support key projects (20JCYBJC01420)。
文摘Electrocatalytic CO_(2) reduction reaction (eCO_(2)RR) presents a promising approach for harnessing renewable energy and converting greenhouse gas (CO_(2)) into high value-added CO products.N-doped single atom (SA) and atomic-level metal nanocluster (MN) tandem catalysts with rich defects for eCO_(2)RR are reported,which achieved a maximum CO Faraday efficiency (FE_(CO)) of 97.7%(-0.7 V vs.RHE) in the H-type cell and maintained over 95% FE_(CO)at potentials from -0.18 to -0.73 V vs.RHE in the flow cell.Furthermore,the catalyst in the flow cell demonstrated a remarkably low onset potential of-0.14 V vs.RHE and the current density was approximately three times that of the H-type cell.Interestingly,XPS analysis indicates that carbon substrates containing defects have more pyridine-N content.DFT calculations and in-situ attenuated total reflection Fourier transform infrared support this finding by showing that the Ni-(N-C_(2))_(3) active sites with defect favors preferentially convert CO_(2)-to-CO.
基金supported by the Korea Basic Science Institute(National research Facilities and Equipment Center)grant funded by the Ministry of Education(No.2019R1A6C1010042)the financial support from the National Research Foundation of Korea(NRF)(2022R1A2C2010686,2022R1A4A3033528,2021R1C1C2010726)。
文摘Herein,we propose a simple and rapid approach for synthesizing a CuS/Ru composite that serves as a bifunctional electrocatalyst to promote hydrogen production and concurrently convert sulfion into a value-added sulfur product.This composite comprises Ru nanoclusters supported on the CuS nanostructure,achieved through simple pulsed laser irradiation in liquid approach.The optimized CuS/Ru-30 electrocatalyst demonstrates remarkable bifunctional electrocatalytic activity,exhibiting a negligible working potential of 0.28 V(vs.RHE)for the anodic sulfion oxidation reaction(SOR)and a minimal overpotential of 182 m V for cathodic hydrogen evolution reaction(HER)to achieve 10 mA cm^(-2)of current density.Moreover,the Cu S/Ru-30 electrocatalyst shows exceptional selectivity for converting sulfion into valuable sulfur during anodic oxidation reactions.Remarkably,in a two-electrode electrolyzer system utilizing Cu S/Ru-30 as both the anode and cathode,the SOR+HER coupled water electrolysis system demands only 0.52 V to reach 10 mA cm^(-2),which is considerably lesser compared to the OER+HER coupled water electrolysis(1.85 V).The experimental results and density function theory(DFT)calculations reveal that the strong electron interaction between CuS and Ru nanoclusters generates a built-in electric field,greatly enhancing electron transfer efficiency.This significantly boosts the HER performance and facilitates the adsorption and production of sulfur intermediates.This study presents a rapid and simple strategy for synthesizing a dual-functional catalyst suitable for low-voltage hydrogen generation while facilitating the recovery of valuable sulfur sources.
文摘The fragile antibody leads to a great challenge as a scaffold to fabricate the luminescent metal nanoclusters using one-pot method.This study presents a stable single-chain anti-body(scFv57R-ATS)for the fabrication of luminescent gold nanoclusters(AuNCs@scFv57R-ATS)and a quick,sensitive rabies virus detection in living cells.In this paper,AuNCs@scFv57R-ATS was designed to specifically recognize antigen RV in modified HeLa cells,which promoted the demonstration of metal nanocluster fluorescent probes for antigen targeting and therapy.
基金supported by the National Natural Science Foundation of China(51672081)the Program of Tri-three Talents Project of Hebei Province(China,A202110002)+1 种基金the Young Top Talents Fund Program of Higher Education Institutions of Heibei Province(BJ2020009)the Project of Science and Technology Innovation Team,Tangshan(20130203D)。
文摘For the use of green hydrogen energy,it is crucial to have efficient photocatalytic activity for hydrogen generation by water reforming of methanol under mild conditions.Much attention has been paid to gC_(3)N_(4)as a promising photocatalyst for the generation of hydrogen.To improve the separation of photogenerated charge,porous nanosheet g-C_(3)N_(4)was modified with Pt nanoclusters(Pt/g-C_(3)N_(4))through impregnation and following photo-induced reduction.This catalyst showed excellent photocatalytic activity of water reforming of methanol fo r hydrogen production with a 17.12 mmol·g^(-1)·h^(-1)rate at room temperature,which was 311 times higher than that of the unmodified g-C_(3)N_(4).The strong interactions of Pt-N in Pt/g-C_(3)N_(4)constructed effective electron transfer channels to promote the separation of photogenerated electrons and holes effectively.In addition,in-situ infrared spectroscopy was used to investigate the intermediates of the hydrogen production reaction,which proved that methanol and water eventually turn into H_(2)and CO_(2)via formaldehyde and formate.This study provides insights for understanding the photocatalytic hydrogen production in the water reforming of methanol.
基金National Natural Science Foundation of China(21908121,22071127)Taishan Scholar Foundation(tsqn201812074,China)Scientific Research Foundation of Qingdao University of Science and Technology(210/010029031,and 210/010029008).
文摘Photocatalytic oxygen(O_(2))reduction has been considered a promising method for hydrogen peroxide(H_(2)O_(2))production.However,the poor visible light harvesting and low-efficient separation and generation of charge carriers of conventional photocatalysts strongly limited their photocatalytic H_(2)O_(2) generation performance.Herein,we design a highly efficient photocatalyst in this work by marrying luminescent gold-silver nanoclusters(AuAg NCs)to polyethyleneimine(PEI)modified C_(3)N_(4)(C3N4-PEI).The key design in this work is the utilization of highly luminescent AuAg NCs as photosensitizers to promote the generation and separation of charge carriers of C_(3)N_(4)-PEI,thereby ultimately producing abundant e−for O_(2) reduction under visible light illumination(λ≥400 nm).As a result,the as-designed photocatalyst(C3N4-PEI-AuAg NCs)exhibits excellent photocatalytic activity with an H_(2)O_(2) production capability of 82μM in pure water,which is 3.5 times higher than pristine C_(3)N_(4)(23μM).This interesting design provides a paradigm in developing other high-efficient photocatalysts for visible-light-driven H_(2)O_(2) production.
基金supported by the Shanxi Province Natural Science Foundation(20210302124446,202102070301018)the Basic Research Project from Institute of Coal Chemistry,CAS(SCJC-HN-2022-17)the Foundation of State Key Laboratory of Coal Conversion(Grant No.J23-24-909).
文摘Water electrolysis via alkaline hydrogen evolution reaction(HER)is a promising approach for large-scale production of high-purity hydrogen at a low cost,utilizing renewable and clean energy.However,the sluggish kinetics derived from the high energy barrier of water dissociation impedes seriously its practical application.Herein,a series of hybrid Pt nanoclusters/Ru nanowires(Pt/Ru NWs)catalysts are demonstrated to accelerate alkaline HER.And the optimized Pt/Ru NWs(10%wt Pt)exhibits exceptional performance with an ultralow overpotential(24 mV at 10 mA cm^(-2)),a small Tafel slope(26.3 mV dec^(-1)),and long-term stability,outperforming the benchmark commercial Pt/C-JM-20%wt catalyst.This amazing performance also occurred in the alkaline anion-exchange membrane water electrolysis devices,where it delivered a cell voltage of about 1.9 V at 1 A cm^(-2)and an outstanding stability(more than 100 h).The calculations have revealed such a superior performance exhibited by Pt/Ru NWs stems from the formed heterointerfaces,which significantly reduce the energy barrier of the decisive rate step of water dissociation via cooperative-action between Pt cluster and Ru substance.This work provides valuable perspectives for designing advanced materials toward alkaline HER and beyond.
基金Agency for Science,Technology,and Research(A*STAR)for providing financial support via SINGA scholarshipthe research support funding from the Newcastle University(RSA/CCEAMD5010)。
文摘The great promise of photodynamic therapy(PDT) has thrusted the rapid progress of developing highly effective photosensitizers(PS) in killing cancerous cells and bacteria. To mitigate the intrinsic limitations of the classical molecular photosensitizers, researchers have been looking into designing new generation of nanomaterial-based photosensitizers(nano-photosensitizers) with better photostability and higher singlet oxygen generation(SOG) efficiency, and ways of enhancing the performance of existing photosensitizers. In this paper, we review the recent development of nano-photosensitizers and nanoplasmonic strategies to enhance the SOG efficiency for better PDT performance. Firstly, we explain the mechanism of reactive oxygen species generation by classical photosensitizers, followed by a brief discussion on the commercially available photosensitizers and their limitations in PDT. We then introduce three types of new generation nanophotosensitizers that can effectively produce singlet oxygen molecules under visible light illumination, i.e., aggregation-induced emission nanodots, metal nanoclusters (< 2 nm), and carbon dots. Different design approaches to synthesize these nano-photosensitizers were also discussed. To further enhance the SOG rate of nano-photosensitizers, plasmonic strategies on using different types of metal nanoparticles in both colloidal and planar metal-PS systems are reviewed. The key parameters that determine the metal-enhanced SOG(ME-SOG) efficiency and their underlined enhancement mechanism are discussed. Lastly, we highlight the future prospects of these nanoengineering strategies, and discuss how the future development in nanobiotechnology and theoretical simulation could accelerate the design of new photosensitizers and ME-SOG systems for highly effective image-guided photodynamic therapy.
基金supports provided by the National Natural Science Foundation of China(U21A2077,21971145,21871164)the Taishan Scholar Project Foundation of Shandong Province(ts20190908)+2 种基金the Natural Science Foundation of Shandong Province(ZR2021ZD05,ZR2019MB024)Young Scholars Program of Shandong University(2017WLJH15)and Anhui Kemi Machinery Technology Co.,Ltd.for providing a Teflon-lined stainless steel autoclave.
文摘Transition metal nitrides have attracted considerable attention as great potential anode materials due to their excellent metallic conductivity and high theoretical specific capacity.However,their cycling performance is impeded by their instability caused by the reaction mechanism.Herein,we report the engineering and synthesis of a novel hybrid architecture composed of MoO2.0N0.5 atomic nanoclusters bonded in nanosheets of N-doped carbon hierarchical hollow microspheres(MoO2.0N0.5/NC)as an anode material for sodium-ion batteries.The facile self-templating strategy for the synthesis of MoO2.0N0.5/NC involves chemical polymerization and subsequent one-step calcination treatments.The design is benefi-cial to improve the electrochemical kinetics,buffer the volume variation of electrodes during cycling,and provide more interfacial active sites for sodium uptake.Due to these unique structural and compositional merits,these MoO2.0N0.5/NC exhibits excellent sodium storage performance in terms of superior rate capability and stable long cycle life.The work shows a feasible and effective way to design novel host candidates and solve the long-term cycling stability issues for sodium-ion batteries.
基金supported by“Shuguang Program”supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission Shaanxi Outstanding Youth Fund(2020JC-49)Youth Innovation Team of University in Shaanxi Province(20SG03)+2 种基金State Key Laboratory of New Textile Materials and Advanced Processing Technologies(No.FZ2021001)Guangdong Basic and Applied Basic Research Foundation(2021A1515110496)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2022JQ-438).
文摘Exploring highly active but inexpensive electrocatalysts for the hydrogen evolution reaction(HER)is of critical importance for hydrogen production from electrochemical water splitting.Herein,we report a multicomponent catalyst with exceptional activity and durability for HER,in which cobalt nanoparticles were in-situ confined inside bamboo-like carbon nanotubes(CNTs)while ultralow ruthenium loading(~2.6μg per electrode area~cm^(−2))is uniformly deposited on their exterior walls(Co@CNTsǀRu).The atomic-scale structural investigations and theoretical calculations indicate that the confined inner Co and loaded outer Ru would induce charge redistribution and a synergistic electron coupling,not only optimizing the adsorption energy of H intermediates(ΔGH*)but also facilitating the electron/mass transfer.The as-developed Co@CNTsǀRu composite catalyst requires overpotentials of only 10,32,and 63 mV to afford a current density of 10 mA cm^(−2) in alkaline,acidic and neutral media,respectively,representing top-level catalytic activity among all reported HER catalysts.The current work may open a new insight into the rational design of carbon-supported metal catalysts for practical applications.
基金financially supported by the National Natural Science Foundation of China(202102007,21978147 and 21935001)the Fundamental Research Funds for the Central Universities(buctrc202112)。
文摘Selective reductive amination of carbonyl compounds with high activity is very essential for the chemical and pharmaceutical industry,but scarcely successful paradigm was reported via efficient photocatalytic reactions.Herein,the ultrasmall Ru nanoclusters(~0.9 nm)were successfully fabricated over P25 support with positive charged Ru^(δ+)species at the interface.A new route was developed to achieve the furfural(FAL)to furfurylamine(FAM)by coupling the light-driven reductive amination and hydrogen transfer of ethanol over this type catalyst.Strikingly,the photocatalytic activity and selectivity are strongly dependent on the particle size and electronic structure of Ruthenium.The Ru^(δ+)species at the interface promote the formation of active imine intermediates;moreover,the Ru nanoclusters facilitate the separation efficiency of electrons and holes as well as accelerate the further hydrogenation of imine intermediates to product primary amines.In contrast Ru particles in larger nanometer size facilitate the formation of the furfuryl alcohol and excessive hydrogenation products.In addition,the coupling byproducts can be effectively inhibited via the construction of sub-nanocluster.This study offers a new path to produce the primary amines from biomass-derived carbonyl compounds over hybrid semiconductor/metal-clusters photocatalyst via light-driven tandem catalytic process.
文摘The NO2 molecule adsorption on B12N12 nano-cage was investigated using density functional theory calculations in terms of adsorption energy, HOMO/LUMO energy gap （Eg） changes, charge transfer, structural deformation, etc. Furthermore, some aspects of stability and properties of B12N12 including calculation of binding electronic and Gibbs free energies, density of states, and molecular electrostatic potential surfaces are investigated. Three possible configurations for NO2 adsorption on the B12N12 nano-cage are energetically found. Interestingly, the results reveals that the Eg of B12N12 cluster is very sensitive to the pres- ence of NO2 molecules as its value reduces from 6.84 eV in free cluster to 3.23 eV in the most stable configuration of NO2/cluster complex. This phenomenon dramatically increases the electrical conductivity of the cluster, suggesting that the B12N12 nano-cluster may be potential sensor for NO2 gaseous molecule detection.
基金The project was supported by the JSPS KAKENH1, Japan (15H03520, 15H03526, and 26107719), and the MEXT-Supported Program for the Strategic Research Foundation at Private Universities, Japan.
文摘Singlet oxygen(1 O2) plays an important role in various applications, such as in the photodynamic therapy(PDT) of cancers,photodynamic inactivation of microorganisms, photo-degradation of toxic compounds, and photo-oxidation in synthetic chemistry. Recently,water-soluble metal nanoclusters(NCs) have been utilized as photosensitizers for the generation of highly reactive 1 O2 because of their high water solubility, low toxicity, and surface functionalizability for targeted substances. In the case of metal NC-based photosensitizers, the photo-physical properties depend on the core size of the NCs and the core/ligand interfacial structures. A wide range of atomically precise gold NCs have been reported; however, reports on the synthesis of atomically precise silver NCs are limited due to the high reactivity and low photostability(i.e., easy oxidation) of Ag NCs. In addition, there have been few reports on what kinds of metal NCs can generate large amounts of 1 O2. In this study, we developed a new one-pot synthesis method of water-soluble Ag7(MBISA)6(MBISA= 2-mercapto-5-benzimidazolesulfonic acid sodium salt) NCs with highly efficient 1 O2 generation ability under the irradiation of white light emitting diodes(LEDs). The molecular formula and purity were determined by electrospray ionization mass spectrometry and gel electrophoresis. To the best of our knowledge, this is the first report on atomically precise thiolate silver clusters(Agn(SR)m) for efficient 1 O2 generation under visible light irradiation. The 1 O2 generation efficiency of Ag7(MBISA)6 NCs was higher than those of the following known water-soluble metal NCs: bovine serum albumin(BSA)-Au25 NCs,BSA-Ag8 NCs, BSA-Ag14 NCs,Ag25(dihydrolipoic acid)14 NCs,Ag35(glutathione)18 NCs,and Ag75(glutathione)40 NCs. The metal NCs examined in this study showed the following order of 1 O2 generation efficiency under white light irradiation: Ag7(MBISA)6 > BSA-Ag14 > Ag75(SG)40 > Ag35(SG)18 >BSA-Au25 >>BSA-Ags(not detected) and Ag2 s(DHLA)14(not detected). For further improving the 1 O2 generation of Ag7(MBISA)6 NCs, we developed a novel fluorescence resonance energy transfer(FRET) system by conjugating Ag7(MBISA)6 NCs with quinacrine(QC)(molar ratio of Ag NCs to QC is 1 : 0.5). We observed the FRET process,from QC to Ag7(MBISA)6 NCs,occurring in the conjugate. That is,the QC works as a donor chromophore,while the Ag NCs work as an acceptor chromophore in the FRET process. The FRET-mediated process caused a 2.3-fold increase in 1 O2 generation compared to that obtained with Ag7(MBISA)6 NCs alone. This study establishes a general and simple strategy for improving the PDT activity of metal NC-based photosensitizers.
基金the National Natu-ral Science Foundation of China(No.21573166 and No.21271146)the Funds for Creative Research Groups of Hubei Province(No.2014CFA007)+2 种基金the Natural Sci-ence Foundation of Jiangsu Province(No.BK20151247)the Science Foundation of Jiangxi Provincial Of-ce of Education(No.GJJ180854)and the Post-Doctoral Start-up Project of Yichun University(NACPB20180201),China.
文摘The development of low-cost, earth-abundant and highly-efficient cocatalysts is still important to promote the photocatalytic H2 evolution reaction over semiconductors. Herein, a series of Ni nanoclusters（NCs） modified brookite TiO2 quasi nanocubes（BTN）（marked as Ni/BTN） are fabricated via a chemical reduction process. It is found that the loading content and oxidation state of Ni NCs can significantly influence the optical absorption, photocatalytic activity, and stability of Ni/BTN composites. Among the resultant Ni NCs-loaded products, 0.1%Ni/BTN composite delivers the best H2 evolution activity（156 μmol/h）,which is 4.3 times higher than that of the BTN alone（36 μmol/h）. Furthermore, the Ni NCs with ultrafine size（2 nm） and high dispersity enable shorter charge transfer distance by quickly capturing the photoexcited electrons of BTN, and thus result in the improved activity even though the oxidization of some Ni NCs on BTN is harmful to the activity for H2 evolution due to the much lower electron capturing capability of NiO than metallic Ni.This study not only clarifies that brookite TiO2 would be a promising high-efficient photocatalyst for H2 evolution, but also reveals vital clues for further improving its photocatalytic performance using low-cost Ni-based cocatalyst.
