With an increase in global aging,the number of people affected by cerebrovascular diseases is also increasing,and the incidence of vascular dementia-closely related to cerebrovascular risk-is increasing at an epidemic...With an increase in global aging,the number of people affected by cerebrovascular diseases is also increasing,and the incidence of vascular dementia-closely related to cerebrovascular risk-is increasing at an epidemic rate.However,few therapeutic options exist that can markedly improve the cognitive impairment and prognosis of vascular dementia patients.Similarly in Alzheimer’s disease and other neurological disorders,synaptic dysfunction is recognized as the main reason for cognitive decline.Nitric oxide is one of the ubiquitous gaseous cellular messengers involved in multiple physiological and pathological processes of the central nervous system.Recently,nitric oxide has been implicated in regulating synaptic plasticity and plays an important role in the pathogenesis of vascular dementia.This review introduces in detail the emerging role of nitric oxide in physiological and pathological states of vascular dementia and summarizes the diverse effects of nitric oxide on different aspects of synaptic dysfunction,neuroinflammation,oxidative stress,and blood-brain barrier dysfunction that underlie the progress of vascular dementia.Additionally,we propose that targeting the nitric oxide-sGC-cGMP pathway using certain specific approaches may provide a novel therapeutic strategy for vascular dementia.展开更多
Nitric oxide(NO)is a gaseous molecule produced by 3 different NO synthase(NOS)isoforms:Neural/brain NOS(nNOS/bNOS,type 1),endothelial NOS(eNOS,type 3)and inducible NOS(type 2).Type 1 and 3 NOS are constitutively expre...Nitric oxide(NO)is a gaseous molecule produced by 3 different NO synthase(NOS)isoforms:Neural/brain NOS(nNOS/bNOS,type 1),endothelial NOS(eNOS,type 3)and inducible NOS(type 2).Type 1 and 3 NOS are constitutively expressed.NO can serve different purposes:As a vasoactive molecule,as a neurotransmitter or as an immunomodulator.It plays a key role in cerebral ischemia/reperfusion injury(CIRI).Hypoxic episodes simulate the production of oxygen free radicals,leading to mitochondrial and phospholipid damage.Upon reperfusion,increased levels of oxygen trigger oxide synthases;whose products are associated with neuronal damage by promoting lipid peroxidation,nitrosylation and excitotoxicity.Molecular pathways in CIRI can be altered by NOS.Neuroprotective effects are observed with eNOS activity.While nNOS interplay is prone to endothelial inflammation,oxidative stress and apoptosis.Therefore,nNOS appears to be detrimental.The interaction between NO and other free radicals develops peroxynitrite;which is a cytotoxic agent.It plays a main role in the likelihood of hemorrhagic events by tissue plasminogen activator(t-PA).Peroxynitrite scavengers are currently being studied as potential targets to prevent hemorrhagic transformation in CIRI.展开更多
Protonic solid oxide electrolysis cells(P-SOECs)are a promising technology for water electrolysis to produce green hydrogen.However,there are still challenges related key materials and anode/electrolyte interface.P-SO...Protonic solid oxide electrolysis cells(P-SOECs)are a promising technology for water electrolysis to produce green hydrogen.However,there are still challenges related key materials and anode/electrolyte interface.P-SOECs with Zr-rich electrolyte,called Zr-rich side P-SOECs,possess high thermodynamically stability under high steam concentrations but the large reaction resistances and the current leakage,thus the inferior performances.In this study,an efficient functional interlayer Ba_(0.95)La_(0.05)Fe_(0.8)Zn_(0.2)O_(3-δ)(BLFZ)in-between the anode and the electrolyte is developed.The electrochemical performances of P-SOECs are greatly enhanced because the BLFZ can greatly increase the interface contact,boost anode reaction kinetics,and increase proton injection into electrolyte.As a result,the P-SOEC yields high current density of 0.83 A cm^(-2) at 600℃ in 1.3 Vamong all the reported Zr-rich side cells.This work not only offers an efficient functional interlayer for P-SOECs but also holds the potential to achieve P-SOECs with high performances and long-term stability.展开更多
Solid oxide electrolysis cells(SOECs)can effectively convert CO_(2)into high value-added CO fuel.In this paper,Sc-doped Sr_(2)Fe_(1.5)Mo_(0.3)Sc_(0.2)O_(6−δ)(SFMSc)perovskite oxide material is synthesized via solid-p...Solid oxide electrolysis cells(SOECs)can effectively convert CO_(2)into high value-added CO fuel.In this paper,Sc-doped Sr_(2)Fe_(1.5)Mo_(0.3)Sc_(0.2)O_(6−δ)(SFMSc)perovskite oxide material is synthesized via solid-phase method as the cathode for CO_(2)electrolysis by SOECs.XRD confirms that SFMSc exhibits a stable cubic phase crystal structure.The experimental results of TPD,TG,EPR,CO_(2)-TPD further demonstrate that Sc-doping increases the concentration of oxygen vacancy in the material and the chemical adsorption capacity of CO_(2)molecules.Electrochemical tests reveal that SFMSc single cell achieves a current density of 2.26 A/cm^(2) and a lower polarization impedance of 0.32Ω·cm^(2) at 800°C under the applied voltage of 1.8 V.And no significant performance attenuation or carbon deposition is observed after 80 h continuous long-term stability test.This study provides a favorable support for the development of SOEC cathode materials with good electro-catalytic performance and stability.展开更多
Solid oxide cells(SOCs)are emerging devices for efficient energy storage and conversion.However,during SOC operation,gaseous chromium(Cr)species released from Fe-Cr alloy interconnect can lead to Cr deposition and poi...Solid oxide cells(SOCs)are emerging devices for efficient energy storage and conversion.However,during SOC operation,gaseous chromium(Cr)species released from Fe-Cr alloy interconnect can lead to Cr deposition and poisoning of air electrodes,causing substantial degradation in electrochemical performance and compromising the longterm stability of SOCs.This mini-review examines the mechanism of Cr deposition and poisoning in air electrodes under both fuel-cell and electrolysis modes.Furthermore,emphasis is placed on the recent advancements in strategies to mitigate Cr poisoning,offering insights into the rational design and development of active and Cr-tolerant air electrodes for SOCs.展开更多
Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage p...Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage poses challenges for the performance and stability of air electrodes.In this work,a novel high-entropy perovskite oxide La_(0.2)Pr_(0.2)Gd_(0.2)Sm_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF)is proposed and investigated as an air electrode in RSOC.The electrochemical behavior of HE-LSCF was studied as an air electrode in both fuel cell and electrolysis modes.The polarization impedance(Rp)of the HE-LSCF electrode is only 0.25Ω·cm^(2) at 800℃ in an air atmosphere.Notably,at an electrolytic voltage of 2 V and a temperature of 800℃,the current density reaches up to 1.68 A/cm^(2).The HE-LSCF air electrode exhibited excellent reversibility and stability,and its electrochemical performance remains stable after 100 h of reversible operation.With these advantages,HE-LSCF is shown to be an excellent air electrode for RSOC.展开更多
Widely used spin-coated nickle oxide (NiOx) based perovskite solar cells often suffer from severe interfacial reactions between the NiOxand adjacent perovskite layers due to surface defect states,which inherently impa...Widely used spin-coated nickle oxide (NiOx) based perovskite solar cells often suffer from severe interfacial reactions between the NiOxand adjacent perovskite layers due to surface defect states,which inherently impair device performance in a long-term view,even with surface molecule passivation.In this study,we developed high-quality magnetron-sputtered NiOxthin films through detailed process optimization,and compared systematically sputtered and spin-coated NiOxthin film surfaces from materials to devices.These sputtered NiOxfilms exhibit improved crystallinity,smoother surfaces,and significantly reduced Ni3+or Ni vacancies compared to their spin-coated counterparts.Consequently,the interface between the perovskite and sputtered NiOxfilm shows a substantially reduced density of defect states.Perovskite solar cells (PSCs) fabricated with our optimally sputtered NiOxfilms achieved a high power conversion efficiency (PCE) of up to 19.93%and demonstrated enhanced stability,maintaining 86.2% efficiency during 500 h of maximum power point tracking under one standard sun illumination.Moreover,with the surface modification using (4-(2,7-dibromo-9,9-dimethylacridin-10(9H)-yl)butyl)p hosphonic acid (DMAcPA),the device PCE was further promoted to 23.07%,which is the highest value reported for sputtered NiOxbased PSCs so far.展开更多
Micrometer-sized silicon oxide(SiO)anodes encounter challenges in large-scale applications due to significant volume expansion during the alloy/de-alloy process.Herein,an innovative deep eutectic electrolyte derived f...Micrometer-sized silicon oxide(SiO)anodes encounter challenges in large-scale applications due to significant volume expansion during the alloy/de-alloy process.Herein,an innovative deep eutectic electrolyte derived from succinonitrile is introduced to enhance the cycling stability of SiO anodes.Density functional theory calculations validate a robust ion-dipole interaction between lithium ions(Li^(+))and succinonitrile(SN).The cosolvent fluoroethylene carbonate(FEC)optimizes the Li^(+)solvation structure in the SN-based electrolyte with its weakly solvating ability.Molecular dynamics simulations investigate the regulating mechanism of ion-dipole and cation-anion interaction.The unique Li^(+)solvation structure,enriched with FEC and TFSI^(-),facilitates the formation of an inorganic-organic composite solid electrolyte interphase on SiO anodes.Micro-CT further detects the inhibiting effect on the SiO volume expansion.As a result,the SiO|LiCoO_(2) full cells exhibit excellent electrochemical performance in deep eutectic-based electrolytes.This work presents an effective strategy for extending the cycle life of SiO anodes by designing a new SN-based deep eutectic electrolyte.展开更多
The Zn-Al spinel oxide stands out as one of the most active catalysts for high-temperature methanol synthesis from CO_(2)hydrogenation.However,the structure–activity relationship of the reaction remains poorly unders...The Zn-Al spinel oxide stands out as one of the most active catalysts for high-temperature methanol synthesis from CO_(2)hydrogenation.However,the structure–activity relationship of the reaction remains poorly understood due to challenges in atomic-level structural characterizations and analysis of reaction intermediates.In this study,we prepared two Zn-Al spinel oxide catalysts via coprecipitation(ZnAl-C)and hydrothermal(ZnAl-H)methods,and conducted a comparative investigation in the CO_(2)hydrogenation reaction.Surprisingly,under similar conditions,ZnAl-C exhibited significantly higher selectivity towards methanol and DME compared to ZnAl-H.Comprehensive characterizations using X-ray diffraction(XRD),Raman spectroscopy and electron paramagnetic resonance(EPR)unveiled that ZnAl-C catalyst had abundant ZnO species on its surface,and the interaction between the ZnO species and its ZnAl spinel oxide matrix led to the formation of oxygen vacancies,which are crucial for CO_(2)adsorption and activation.Additionally,state-of-the-art solid-state nuclear magnetic resonance(NMR)techniques,including ex-situ and in-situ NMR analyses,confirmed that the surface ZnO facilitates the formation of unique highly reactive interfacial formate species,which was readily hydrogenated to methanol and DME.These insights elucidate the promotion effects of ZnO on the ZnAl spinel oxide in regulating active sites and reactive intermediates for CO_(2)-to-methanol hydrogenation reaction,which is further evidenced by the significant enhancement in methanol and DME selectivity observed upon loading ZnO onto the ZnAl-H catalyst.These molecular-level mechanism understandings reinforce the idea of optimizing the ZnO-ZnAl interface through tailored synthesis methods to achieve activity-selectivity balance.展开更多
Conventional Fe-C alloy parts used in mechanical transmission and braking systems exposed to the external environment often suffer from wear and corrosion failures.Surface coating strengthening technologies have been ...Conventional Fe-C alloy parts used in mechanical transmission and braking systems exposed to the external environment often suffer from wear and corrosion failures.Surface coating strengthening technologies have been explored to improve the surface performance and prolong service life of these parts.Among these technologies,laser cladding has shown promise in producing Fe-based alloy coatings with superior interfacial bonding properties to the Fe-C alloy substrate.Additionally,the microstructure of the Fe-based alloy coating is more uniform and the grain size is finer than that of surfacing welding,thermal spraying,and plasma cladding,and the oxide film of alloying elements on the coating surface can improve the coating performance.However,Fe-based alloy coatings produced by laser cladding typically exhibit lower hardness,lower wear resistance,corrosion resistance,and oxidation resistance compared to coatings based on Co and Ni alloys.Moreover,these coatings are susceptible to defects such as pores and cracks.To address these limitations,the incorporation of rare-earth oxides through doping in the laser cladding process has garnered significant attention.This approach has demonstrated substantial improvements in the microstructure and properties of Fe-based alloy coatings.This paper reviewed recent research on the structure and properties of laser-cladded Fe-based alloy coatings doped with various rare earth oxides,including La_(2)O_(3),CeO_(2),and Y_(2)O_(3).Specifically,it discussed the effects of rare earth oxides and their concentrations on the structure,hardness,friction,wear,corrosion,and oxidation characteristics of these coatings.Furthermore,the mechanisms by which rare earth oxides influence the coating’s structure and properties were summarized.This review aimed to serve as a valuable reference for the application and advancement of laser cladding technology for rare earth modified Fe-based alloy coatings.展开更多
High-entropy materials have become high-activity electrocatalysis owing to their high-entropy effect and multiple active sites.Herein,we synthesize a series of carbon-supported nano high-entropy oxides(HEOs/C),specifi...High-entropy materials have become high-activity electrocatalysis owing to their high-entropy effect and multiple active sites.Herein,we synthesize a series of carbon-supported nano high-entropy oxides(HEOs/C),specifically (PtFeCoNiCu)O/C,using a carbothermal shock (CTS) method for application as a cathode catalyst in direct borohydride fuel cells (DBFCs).The microstructure of the prepared catalysts was characterized by X-ray photoelectron spectroscopy,X-ray absorption fine structure,and transmission electron microscopy.The prepared (PtFeCoNiCu)O/C,with particle sizes ranging from 2 to 4 nm,demonstrates 3.94 transferred electrons towards the oxygen reduction reaction in an alkaline environment,resulting in a minimal H_(2)O_(2)yield of 2.6%.Additionally,it exhibits a Tafel slope of 61 mV dec-1,surpassing that of commercial Pt/C (82 mV dec-1).Furthermore,after 40,000 cycles of cyclic voltammetry(CV) testing,the half-wave potential of (PtFeCoNiCu)O/C shows a positive shift of 3 mV,with no notable decline in the limiting current density.When (PtFeCoNiCu)O/C is used as a cathode catalyst in DBFCs,the DBFC achieves a maximum power density of 441 mW cm^(-2)at 60°C and sustains a cell voltage of approximately 0.73 V after 52 h at 30°C.These findings confirm that HEO/C is a promising cathode catalyst for DBFCs.展开更多
Hydrogen (H2) production from renewable biomass resources plays a significant role in solving the shortage of fossil energy;hence, there is an interest in investigating alternative, cleaner processes. This work intend...Hydrogen (H2) production from renewable biomass resources plays a significant role in solving the shortage of fossil energy;hence, there is an interest in investigating alternative, cleaner processes. This work intends to study the photocatalytic production of hydrogen from D-(+)-Glucose by using different groups of catalysts that have been prepared (M2+ = Zn, Mg and Ni) M2+/Ti4+ Al3+-LDHs (layered double hydroxides). It is then loaded Pd on the catalyst, and the effect of the composite catalyst, layered double hydroxides, is measured. After calcining, the catalyst for the conversion of Layered Double Hydroxides (LDHs) to Layered Double Oxides (LDOs) is used to produce hydrogen gas from glucose. Photocatalytic reforming of glucose-derived compounds is an efficient method for the production of hydrogen. The purpose is to study the effect of metal ions on layered double oxide (LDO) materials by loading Pd and investigate hydrogen production from glucose. The metal cations in the layer were distributed through the preparation of the catalyst process by ion and atom scale between the layers, which were dispersed systematically, as well as the controlled component catalysis. This process shows that ZnTiAl-LDO had the best effect as a catalyst in producing hydrogen compared to NiTiAl-LDO and MgTiAl-LDO.展开更多
Lithium-rich layered oxides (LLOs) are increasingly recognized as promising cathode materials for nextgeneration high-energy-density lithium-ion batteries (LIBs).However,they suffer from voltage decay and low initial ...Lithium-rich layered oxides (LLOs) are increasingly recognized as promising cathode materials for nextgeneration high-energy-density lithium-ion batteries (LIBs).However,they suffer from voltage decay and low initial Coulombic efficiency (ICE) due to severe structural degradation caused by irreversible O release.Herein,we introduce a three-in-one strategy of increasing Ni and Mn content,along with Li/Ni disordering and TM–O covalency regulation to boost cationic and anionic redox activity simultaneously and thus enhance the electrochemical activity of LLOs.The target material,Li_(1.2)Ni_(0.168)Mn_(0.558)Co_(0.074)O_(2)(L1),exhibits an improved ICE of 87.2%and specific capacity of 293.2 mA h g^(-1)and minimal voltage decay of less than 0.53 m V cycle-1over 300 cycles at 1C,compared to Li_(1.2)Ni_(0.13)Mn_(0.54)Co_(0.13)O_(2)(Ls)(274.4 mA h g^(-1)for initial capacity,73.8%for ICE and voltage decay of 0.84 mV/cycle over 300 cycles at 1C).Theoretical calculations reveal that the density of states (DOS) area near the Fermi energy level for L1 is larger than that of Ls,indicating higher anionic and cationic redox reactivity than Ls.Moreover,L1 exhibits increased O-vacancy formation energy due to higher Li/Ni disordering of 4.76%(quantified by X-ray diffraction Rietveld refinement) and enhanced TM–O covalency,making lattice O release more difficult and thus improving electrochemical stability.The increased Li/Ni disordering also leads to more Ni^(2+)presence in the Li layer,which acts as a pillar during Li+de-embedding,improving structural stability.This research not only presents a viable approach to designing low-Co LLOs with enhanced capacity and ICE but also contributes significantly to the fundamental understanding of structural regulation in high-performance LIB cathodes.展开更多
A microreactor system was used to study the catalytic reaction of NO+CO→1/2 N_2+CO_2 over Cu,Fe, Mn,Cr,and Ce oxides supported on alumina,and the effect of adding Ce in supported Cu-M-O(M=Mn,Fe and Cr) catalysts on t...A microreactor system was used to study the catalytic reaction of NO+CO→1/2 N_2+CO_2 over Cu,Fe, Mn,Cr,and Ce oxides supported on alumina,and the effect of adding Ce in supported Cu-M-O(M=Mn,Fe and Cr) catalysts on their catalytic activities for the topic reaction and the concentration of N_2O produced.It was found that the catalytic activity order of the single-element oxide is:CuO>Fe_2O_3≈Cr_2O_3> MnO_2>CeO_2>NiO.Cu-Mn-O is more active than CuO,and Cu-Fe-O is more active than Cu-Mn-O and Cu-Cr-O for NO+CO reaction.This study shows that the addition of Ce in supported Cu-M-O can promote their catalytic activities Jot the topic reaction,which makes the reaction of 2NO+CO→N_2O+CO_2 fast,and N_2O is an intermediate compound produced during NO+CO reaction.展开更多
Carbon monoxide(CO)and nitric oxide(NO)are signal molecules that enhance plant adaptation to environmental stimuli.Auxin is an essential phytohormone for plant growth and development.CO and NO play crucial roles in mo...Carbon monoxide(CO)and nitric oxide(NO)are signal molecules that enhance plant adaptation to environmental stimuli.Auxin is an essential phytohormone for plant growth and development.CO and NO play crucial roles in modulating the plant’s response to iron deficiency.Iron deficiency leads to an increase in the activity of heme oxygenase(HO)and the subsequent generation of CO.Additionally,it alters the polar subcellular distribution of Pin-Formed 1(PIN1)proteins,resulting in enhanced auxin transport.This alteration,in turn,leads to an increase in NO accumulation.Furthermore,iron deficiency enhances the activity of ferric chelate reductase(FCR),as well as the expression of the Fer-like iron deficiency-induced transcription factor 1(FIT)and the ferric reduction oxidase 2(FRO2)genes in plant roots.Overexpression of the long hypocotyl 1(HY1)gene,which encodes heme oxygenase,or the CO donor treatment resulted in enhanced basipetal auxin transport,higher FCR activity,and the expression of FIT and FRO2 genes under Fe deficiency.Here,a potential mechanism is proposed:CO and NO interact with auxin to address iron deficiency stress.CO alters auxin transport,enhancing its accumulation in roots and up-regulating key iron-related genes like FRO2 and IRT1.Elevated auxin levels affect NO signaling,leading to greater sensitivity in root development.This interplay promotes FCR activity,which is crucial for iron absorption.Together,these molecules enhance iron uptake and root growth,revealing a novel aspect of plant physiology in adapting to environmental stress.展开更多
The global energy-related CO_(2) emissions have rapidly increased as the world economy heavily relied on fossil fuels.This paper explores the pressing challenge of CO_(2) emissions and highlights the role of porous me...The global energy-related CO_(2) emissions have rapidly increased as the world economy heavily relied on fossil fuels.This paper explores the pressing challenge of CO_(2) emissions and highlights the role of porous metal oxide materials in the electrocatalytic reduction of CO_(2)(CO_(2)RR).The focus is on the development of robust and selective catalysts,particularly metal and metal-oxide-based materials.Porous metal oxides offer high surface area,enhancing the accessibility to active sites and improving reaction kinetics.The tunability of these materials allows for tailored catalytic behavior,targeting optimized reaction mechanisms for CO_(2)RR.The work also discusses the various synthesis strategies and identifies key structural and compositional features,addressing challenges like high overpotential,poor selectivity,and low stability.Based on these insights,we suggest avenues for future research on porous metal oxide materials for electrochemical CO_(2) reduction.展开更多
The hydrothermal synthesis of In_(2)O_(3)and CeO_(2)–In_(2)O_(3)is investigated as well as the properties of sensor layers based on these compounds.During the synthesis of In_(2)O_(3),intermediate products In(OH)_(3)...The hydrothermal synthesis of In_(2)O_(3)and CeO_(2)–In_(2)O_(3)is investigated as well as the properties of sensor layers based on these compounds.During the synthesis of In_(2)O_(3),intermediate products In(OH)_(3)and InOOH are formed,which are the precursors of stable cubic(c-In_(2)O_(3))and metastable rhombohedral(rh-In_(2)O_(3))phases,respectively.A transition from c-In_(2)O_(3)to rh-In_(2)O_(3)is observed with the addition of CeO_(2).The introduction of cerium into rh-In_(2)O_(3)results in a decrease in the sensor response to hydrogen,while it increases in composites based on c-In_(2)O_(3).The data on the sensor activity of the composites correlate with XPS results in which CeO_(2)causes a decrease in the concentrations of chemisorbed oxygen and oxygen vacancies in rh-In_(2)O_(3).The reverse situation is observed in composites based on c-In_(2)O_(3).Compared to In_(2)O_(3)and CeO_(2)–In_(2)O_(3)obtained by other methods,the synthesized composites demonstrate maximum response to H_(2)at low temperatures by 70–100℃,and have short response time(0.2–0.5 s),short recovery time(6–7 s),and long-term stability.A model is proposed for the dependence of sensitivity on the direction of electron transfer between In_(2)O_(3)and CeO_(2).展开更多
The bioreduction of graphene oxide(GO)using environmentally functional bacteria such as Shewanella represents a green approach to produce reduced graphene oxide(rGO).This process differs from the chemical reduction th...The bioreduction of graphene oxide(GO)using environmentally functional bacteria such as Shewanella represents a green approach to produce reduced graphene oxide(rGO).This process differs from the chemical reduction that involves instantaneous molecular reactions.In bioreduction,the contact of bacterial cells and GO is considered the rate-limiting step.To reveal how the bacteria-GO integration regulates rGO production,the comparative experiments of GO and three Shewanella strains were carried out.Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy,Raman spectroscopy,and atomic force microscopy were used to characterize the reduction degree and the aggregation degree.The results showed that a spontaneous aggregation of GO and Shewanella into the condensed entity occurred within 36 h.A positive linear correlation was established,linking three indexes of the aggregation potential,the bacterial reduction ability,and the reduction degree(ID/IG)comprehensively.展开更多
Metal oxide mesocrystals are the alignment of metal oxide nanoparticles building blocks into the ordered superstructure,which have potentially tunable optical,electronic,and electrical properties suitable for practica...Metal oxide mesocrystals are the alignment of metal oxide nanoparticles building blocks into the ordered superstructure,which have potentially tunable optical,electronic,and electrical properties suitable for practical applications.Herein,we report an effective method for synthesizing mesocrystal zinc oxide nanorods(ZnONRs).The crystal,surface,and internal structures of the zinc oxide mesocrystals were fully characterized.Mesocrystal zinc oxide nanorods/reduced graphene oxide(ZnONRs/rGO)nanocomposite superstructure were synthesized also using the hydrothermal method.The crystal,surface,chemical,and internal structures of the ZnONRs/rGO nanocomposite superstructure were also fully characterized.The optical absorption coefficient,bandgap energy,band structure,and electrical conductivity of the ZnONRs/rGO nanocomposite superstructure were investigated to understand its optoelectronic and electrical properties.Finally,the photoconductivity of the ZnONRs/rGO nanocomposite superstructure was explored to find the possibilities of using this nanocomposite superstructure for ultraviolet(UV)photodetection applications.Finally,we concluded that the ZnONRs/rGO nanocomposite superstructure has high UV sensitivity and is suitable for UV detector applications.展开更多
The study of oxide heteroepitaxy has been hindered by the issues of misfit strain and substrate clamping,which impede both the optimization of performance and the acquisition of a fundamental understanding of oxide sy...The study of oxide heteroepitaxy has been hindered by the issues of misfit strain and substrate clamping,which impede both the optimization of performance and the acquisition of a fundamental understanding of oxide systems.Recently,however,the development of freestanding oxide membranes has provided a plausible solution to these substrate limitations.Single-crystalline functional oxide films can be released from their substrates without incurring significant damage and can subsequently be transferred to any substrate of choice.This paper discusses recent advancements in the fabrication,adjustable physical properties,and various applications of freestanding oxide perovskite films.First,we present the primary strategies employed for the synthesis and transfer of these freestanding perovskite thin films.Second,we explore the main functionalities observed in freestanding perovskite oxide thin films,with special attention to the tunable functionalities and physical properties of these freestanding perovskite membranes under varying strain states.Next,we encapsulate three representative devices based on freestanding oxide films.Overall,this review highlights the potential of freestanding oxide films for the study of novel functionalities and flexible electronics.展开更多
基金supported by the National Key R&D Program of China,No.2019YFE0121200(to LQZ)the National Natural Science Foundation of China,Nos.82325017(to LQZ),82030032(to LQZ),82261138555(to DL)+2 种基金the Natural Science Foundation of Hubei Province,No.2022CFA004(to LQZ)the Natural Science Foundation of Jiangxi Province,No.20224BAB206040(to XZ)Research Project of Cognitive Science and Transdisciplinary Studies Center of Jiangxi Province,No.RZYB202201(to XZ).
文摘With an increase in global aging,the number of people affected by cerebrovascular diseases is also increasing,and the incidence of vascular dementia-closely related to cerebrovascular risk-is increasing at an epidemic rate.However,few therapeutic options exist that can markedly improve the cognitive impairment and prognosis of vascular dementia patients.Similarly in Alzheimer’s disease and other neurological disorders,synaptic dysfunction is recognized as the main reason for cognitive decline.Nitric oxide is one of the ubiquitous gaseous cellular messengers involved in multiple physiological and pathological processes of the central nervous system.Recently,nitric oxide has been implicated in regulating synaptic plasticity and plays an important role in the pathogenesis of vascular dementia.This review introduces in detail the emerging role of nitric oxide in physiological and pathological states of vascular dementia and summarizes the diverse effects of nitric oxide on different aspects of synaptic dysfunction,neuroinflammation,oxidative stress,and blood-brain barrier dysfunction that underlie the progress of vascular dementia.Additionally,we propose that targeting the nitric oxide-sGC-cGMP pathway using certain specific approaches may provide a novel therapeutic strategy for vascular dementia.
文摘Nitric oxide(NO)is a gaseous molecule produced by 3 different NO synthase(NOS)isoforms:Neural/brain NOS(nNOS/bNOS,type 1),endothelial NOS(eNOS,type 3)and inducible NOS(type 2).Type 1 and 3 NOS are constitutively expressed.NO can serve different purposes:As a vasoactive molecule,as a neurotransmitter or as an immunomodulator.It plays a key role in cerebral ischemia/reperfusion injury(CIRI).Hypoxic episodes simulate the production of oxygen free radicals,leading to mitochondrial and phospholipid damage.Upon reperfusion,increased levels of oxygen trigger oxide synthases;whose products are associated with neuronal damage by promoting lipid peroxidation,nitrosylation and excitotoxicity.Molecular pathways in CIRI can be altered by NOS.Neuroprotective effects are observed with eNOS activity.While nNOS interplay is prone to endothelial inflammation,oxidative stress and apoptosis.Therefore,nNOS appears to be detrimental.The interaction between NO and other free radicals develops peroxynitrite;which is a cytotoxic agent.It plays a main role in the likelihood of hemorrhagic events by tissue plasminogen activator(t-PA).Peroxynitrite scavengers are currently being studied as potential targets to prevent hemorrhagic transformation in CIRI.
基金financial support from the JSPS KAKENHI Grant-in-Aid for Scientific Research(B),No.21H02035KAKENHI Grant-in-Aid for Challenging Research(Exploratory),No.21K19017+2 种基金KAKENHI Grant-in-Aid for Transformative Research Areas(B),No.21H05100National Natural Science Foundation of China,No.22409033 and No.22409035Basic and Applied Basic Research Foundation of Guangdong Province,No.2022A1515110470.
文摘Protonic solid oxide electrolysis cells(P-SOECs)are a promising technology for water electrolysis to produce green hydrogen.However,there are still challenges related key materials and anode/electrolyte interface.P-SOECs with Zr-rich electrolyte,called Zr-rich side P-SOECs,possess high thermodynamically stability under high steam concentrations but the large reaction resistances and the current leakage,thus the inferior performances.In this study,an efficient functional interlayer Ba_(0.95)La_(0.05)Fe_(0.8)Zn_(0.2)O_(3-δ)(BLFZ)in-between the anode and the electrolyte is developed.The electrochemical performances of P-SOECs are greatly enhanced because the BLFZ can greatly increase the interface contact,boost anode reaction kinetics,and increase proton injection into electrolyte.As a result,the P-SOEC yields high current density of 0.83 A cm^(-2) at 600℃ in 1.3 Vamong all the reported Zr-rich side cells.This work not only offers an efficient functional interlayer for P-SOECs but also holds the potential to achieve P-SOECs with high performances and long-term stability.
基金supported by National Key R&D Program of China(2021YFB4001401)National Natural Science Foundation of China(52272190,22178023).
文摘Solid oxide electrolysis cells(SOECs)can effectively convert CO_(2)into high value-added CO fuel.In this paper,Sc-doped Sr_(2)Fe_(1.5)Mo_(0.3)Sc_(0.2)O_(6−δ)(SFMSc)perovskite oxide material is synthesized via solid-phase method as the cathode for CO_(2)electrolysis by SOECs.XRD confirms that SFMSc exhibits a stable cubic phase crystal structure.The experimental results of TPD,TG,EPR,CO_(2)-TPD further demonstrate that Sc-doping increases the concentration of oxygen vacancy in the material and the chemical adsorption capacity of CO_(2)molecules.Electrochemical tests reveal that SFMSc single cell achieves a current density of 2.26 A/cm^(2) and a lower polarization impedance of 0.32Ω·cm^(2) at 800°C under the applied voltage of 1.8 V.And no significant performance attenuation or carbon deposition is observed after 80 h continuous long-term stability test.This study provides a favorable support for the development of SOEC cathode materials with good electro-catalytic performance and stability.
基金supported by National Natural Science Foundation of China(22279018)National Natural Science Foundation of China(22005055)Natural Science Foundation of Fujian Province(2022J01085).
文摘Solid oxide cells(SOCs)are emerging devices for efficient energy storage and conversion.However,during SOC operation,gaseous chromium(Cr)species released from Fe-Cr alloy interconnect can lead to Cr deposition and poisoning of air electrodes,causing substantial degradation in electrochemical performance and compromising the longterm stability of SOCs.This mini-review examines the mechanism of Cr deposition and poisoning in air electrodes under both fuel-cell and electrolysis modes.Furthermore,emphasis is placed on the recent advancements in strategies to mitigate Cr poisoning,offering insights into the rational design and development of active and Cr-tolerant air electrodes for SOCs.
基金supported by Fundamental Research Funds for the Central Universities(2023KYJD1008)the Science Research Projects of the Anhui Higher Education Institutions of China(2022AH051582).
文摘Reversible solid oxide cell(RSOC)is a new energy conversion device with significant applications,especially for power grid peaking shaving.However,the reversible conversion process of power generation/energy storage poses challenges for the performance and stability of air electrodes.In this work,a novel high-entropy perovskite oxide La_(0.2)Pr_(0.2)Gd_(0.2)Sm_(0.2)Sr_(0.2)Co_(0.8)Fe_(0.2)O_(3−δ)(HE-LSCF)is proposed and investigated as an air electrode in RSOC.The electrochemical behavior of HE-LSCF was studied as an air electrode in both fuel cell and electrolysis modes.The polarization impedance(Rp)of the HE-LSCF electrode is only 0.25Ω·cm^(2) at 800℃ in an air atmosphere.Notably,at an electrolytic voltage of 2 V and a temperature of 800℃,the current density reaches up to 1.68 A/cm^(2).The HE-LSCF air electrode exhibited excellent reversibility and stability,and its electrochemical performance remains stable after 100 h of reversible operation.With these advantages,HE-LSCF is shown to be an excellent air electrode for RSOC.
基金National Natural Science Foundation of China (NSFC)(52273266, U2001216)Shenzhen Science and Technology Innovation Committee (20231121102401001)+2 种基金Shenzhen Key Laboratory Project (ZDSYS201602261933302)GuangdongHong Kong-Macao Joint Laboratory on Micro-Nano Manufacturing Technology (2021LSYS004)SUSTech high level special funds (G03050K002)。
文摘Widely used spin-coated nickle oxide (NiOx) based perovskite solar cells often suffer from severe interfacial reactions between the NiOxand adjacent perovskite layers due to surface defect states,which inherently impair device performance in a long-term view,even with surface molecule passivation.In this study,we developed high-quality magnetron-sputtered NiOxthin films through detailed process optimization,and compared systematically sputtered and spin-coated NiOxthin film surfaces from materials to devices.These sputtered NiOxfilms exhibit improved crystallinity,smoother surfaces,and significantly reduced Ni3+or Ni vacancies compared to their spin-coated counterparts.Consequently,the interface between the perovskite and sputtered NiOxfilm shows a substantially reduced density of defect states.Perovskite solar cells (PSCs) fabricated with our optimally sputtered NiOxfilms achieved a high power conversion efficiency (PCE) of up to 19.93%and demonstrated enhanced stability,maintaining 86.2% efficiency during 500 h of maximum power point tracking under one standard sun illumination.Moreover,with the surface modification using (4-(2,7-dibromo-9,9-dimethylacridin-10(9H)-yl)butyl)p hosphonic acid (DMAcPA),the device PCE was further promoted to 23.07%,which is the highest value reported for sputtered NiOxbased PSCs so far.
基金supported by the National Natural Science Foundation of China(22279026)the National Key Research and Development Program of China(2022YFE0138900)+2 种基金the Young Elite Scientist sponsorship program by CAST(no.20200148)the Natural Science Funds of Heilongjiang Province(YQ2021B003)the Fundamental Research Funds for the Central Universities(grant no.HIT.OCEF.2022017).
文摘Micrometer-sized silicon oxide(SiO)anodes encounter challenges in large-scale applications due to significant volume expansion during the alloy/de-alloy process.Herein,an innovative deep eutectic electrolyte derived from succinonitrile is introduced to enhance the cycling stability of SiO anodes.Density functional theory calculations validate a robust ion-dipole interaction between lithium ions(Li^(+))and succinonitrile(SN).The cosolvent fluoroethylene carbonate(FEC)optimizes the Li^(+)solvation structure in the SN-based electrolyte with its weakly solvating ability.Molecular dynamics simulations investigate the regulating mechanism of ion-dipole and cation-anion interaction.The unique Li^(+)solvation structure,enriched with FEC and TFSI^(-),facilitates the formation of an inorganic-organic composite solid electrolyte interphase on SiO anodes.Micro-CT further detects the inhibiting effect on the SiO volume expansion.As a result,the SiO|LiCoO_(2) full cells exhibit excellent electrochemical performance in deep eutectic-based electrolytes.This work presents an effective strategy for extending the cycle life of SiO anodes by designing a new SN-based deep eutectic electrolyte.
基金financially National Key R&D Program of China(No.2022YFA1504800)National Natural Science Foundation of China(Grant No.22325405,22372160,22321002)+1 种基金Liaoning Revitalization Talents Program(XLYC1807207)DICP I202104。
文摘The Zn-Al spinel oxide stands out as one of the most active catalysts for high-temperature methanol synthesis from CO_(2)hydrogenation.However,the structure–activity relationship of the reaction remains poorly understood due to challenges in atomic-level structural characterizations and analysis of reaction intermediates.In this study,we prepared two Zn-Al spinel oxide catalysts via coprecipitation(ZnAl-C)and hydrothermal(ZnAl-H)methods,and conducted a comparative investigation in the CO_(2)hydrogenation reaction.Surprisingly,under similar conditions,ZnAl-C exhibited significantly higher selectivity towards methanol and DME compared to ZnAl-H.Comprehensive characterizations using X-ray diffraction(XRD),Raman spectroscopy and electron paramagnetic resonance(EPR)unveiled that ZnAl-C catalyst had abundant ZnO species on its surface,and the interaction between the ZnO species and its ZnAl spinel oxide matrix led to the formation of oxygen vacancies,which are crucial for CO_(2)adsorption and activation.Additionally,state-of-the-art solid-state nuclear magnetic resonance(NMR)techniques,including ex-situ and in-situ NMR analyses,confirmed that the surface ZnO facilitates the formation of unique highly reactive interfacial formate species,which was readily hydrogenated to methanol and DME.These insights elucidate the promotion effects of ZnO on the ZnAl spinel oxide in regulating active sites and reactive intermediates for CO_(2)-to-methanol hydrogenation reaction,which is further evidenced by the significant enhancement in methanol and DME selectivity observed upon loading ZnO onto the ZnAl-H catalyst.These molecular-level mechanism understandings reinforce the idea of optimizing the ZnO-ZnAl interface through tailored synthesis methods to achieve activity-selectivity balance.
基金supported by the Jiangxi Provincial Natural Science Foundation of China(Grant number 20224BAB204049)the National Natural Science Foundation of China(Grant number 52205194)the Fund Project of Jiangxi Provincial Department of Education(Grant number GJJ2200602)。
文摘Conventional Fe-C alloy parts used in mechanical transmission and braking systems exposed to the external environment often suffer from wear and corrosion failures.Surface coating strengthening technologies have been explored to improve the surface performance and prolong service life of these parts.Among these technologies,laser cladding has shown promise in producing Fe-based alloy coatings with superior interfacial bonding properties to the Fe-C alloy substrate.Additionally,the microstructure of the Fe-based alloy coating is more uniform and the grain size is finer than that of surfacing welding,thermal spraying,and plasma cladding,and the oxide film of alloying elements on the coating surface can improve the coating performance.However,Fe-based alloy coatings produced by laser cladding typically exhibit lower hardness,lower wear resistance,corrosion resistance,and oxidation resistance compared to coatings based on Co and Ni alloys.Moreover,these coatings are susceptible to defects such as pores and cracks.To address these limitations,the incorporation of rare-earth oxides through doping in the laser cladding process has garnered significant attention.This approach has demonstrated substantial improvements in the microstructure and properties of Fe-based alloy coatings.This paper reviewed recent research on the structure and properties of laser-cladded Fe-based alloy coatings doped with various rare earth oxides,including La_(2)O_(3),CeO_(2),and Y_(2)O_(3).Specifically,it discussed the effects of rare earth oxides and their concentrations on the structure,hardness,friction,wear,corrosion,and oxidation characteristics of these coatings.Furthermore,the mechanisms by which rare earth oxides influence the coating’s structure and properties were summarized.This review aimed to serve as a valuable reference for the application and advancement of laser cladding technology for rare earth modified Fe-based alloy coatings.
基金Zhejiang Provincial Natural Science Foundation of China (LZ22B060001,LY22E010003)“Pioneer” R&D Program of Zhejiang Province(2023C01080)National Natural Science Foundation of China (52301235)。
文摘High-entropy materials have become high-activity electrocatalysis owing to their high-entropy effect and multiple active sites.Herein,we synthesize a series of carbon-supported nano high-entropy oxides(HEOs/C),specifically (PtFeCoNiCu)O/C,using a carbothermal shock (CTS) method for application as a cathode catalyst in direct borohydride fuel cells (DBFCs).The microstructure of the prepared catalysts was characterized by X-ray photoelectron spectroscopy,X-ray absorption fine structure,and transmission electron microscopy.The prepared (PtFeCoNiCu)O/C,with particle sizes ranging from 2 to 4 nm,demonstrates 3.94 transferred electrons towards the oxygen reduction reaction in an alkaline environment,resulting in a minimal H_(2)O_(2)yield of 2.6%.Additionally,it exhibits a Tafel slope of 61 mV dec-1,surpassing that of commercial Pt/C (82 mV dec-1).Furthermore,after 40,000 cycles of cyclic voltammetry(CV) testing,the half-wave potential of (PtFeCoNiCu)O/C shows a positive shift of 3 mV,with no notable decline in the limiting current density.When (PtFeCoNiCu)O/C is used as a cathode catalyst in DBFCs,the DBFC achieves a maximum power density of 441 mW cm^(-2)at 60°C and sustains a cell voltage of approximately 0.73 V after 52 h at 30°C.These findings confirm that HEO/C is a promising cathode catalyst for DBFCs.
文摘Hydrogen (H2) production from renewable biomass resources plays a significant role in solving the shortage of fossil energy;hence, there is an interest in investigating alternative, cleaner processes. This work intends to study the photocatalytic production of hydrogen from D-(+)-Glucose by using different groups of catalysts that have been prepared (M2+ = Zn, Mg and Ni) M2+/Ti4+ Al3+-LDHs (layered double hydroxides). It is then loaded Pd on the catalyst, and the effect of the composite catalyst, layered double hydroxides, is measured. After calcining, the catalyst for the conversion of Layered Double Hydroxides (LDHs) to Layered Double Oxides (LDOs) is used to produce hydrogen gas from glucose. Photocatalytic reforming of glucose-derived compounds is an efficient method for the production of hydrogen. The purpose is to study the effect of metal ions on layered double oxide (LDO) materials by loading Pd and investigate hydrogen production from glucose. The metal cations in the layer were distributed through the preparation of the catalyst process by ion and atom scale between the layers, which were dispersed systematically, as well as the controlled component catalysis. This process shows that ZnTiAl-LDO had the best effect as a catalyst in producing hydrogen compared to NiTiAl-LDO and MgTiAl-LDO.
基金National Natural Science Foundation of China (No.52202046)Natural Science Foundation of Shaanxi Province (No.2021JQ-034)。
文摘Lithium-rich layered oxides (LLOs) are increasingly recognized as promising cathode materials for nextgeneration high-energy-density lithium-ion batteries (LIBs).However,they suffer from voltage decay and low initial Coulombic efficiency (ICE) due to severe structural degradation caused by irreversible O release.Herein,we introduce a three-in-one strategy of increasing Ni and Mn content,along with Li/Ni disordering and TM–O covalency regulation to boost cationic and anionic redox activity simultaneously and thus enhance the electrochemical activity of LLOs.The target material,Li_(1.2)Ni_(0.168)Mn_(0.558)Co_(0.074)O_(2)(L1),exhibits an improved ICE of 87.2%and specific capacity of 293.2 mA h g^(-1)and minimal voltage decay of less than 0.53 m V cycle-1over 300 cycles at 1C,compared to Li_(1.2)Ni_(0.13)Mn_(0.54)Co_(0.13)O_(2)(Ls)(274.4 mA h g^(-1)for initial capacity,73.8%for ICE and voltage decay of 0.84 mV/cycle over 300 cycles at 1C).Theoretical calculations reveal that the density of states (DOS) area near the Fermi energy level for L1 is larger than that of Ls,indicating higher anionic and cationic redox reactivity than Ls.Moreover,L1 exhibits increased O-vacancy formation energy due to higher Li/Ni disordering of 4.76%(quantified by X-ray diffraction Rietveld refinement) and enhanced TM–O covalency,making lattice O release more difficult and thus improving electrochemical stability.The increased Li/Ni disordering also leads to more Ni^(2+)presence in the Li layer,which acts as a pillar during Li+de-embedding,improving structural stability.This research not only presents a viable approach to designing low-Co LLOs with enhanced capacity and ICE but also contributes significantly to the fundamental understanding of structural regulation in high-performance LIB cathodes.
文摘A microreactor system was used to study the catalytic reaction of NO+CO→1/2 N_2+CO_2 over Cu,Fe, Mn,Cr,and Ce oxides supported on alumina,and the effect of adding Ce in supported Cu-M-O(M=Mn,Fe and Cr) catalysts on their catalytic activities for the topic reaction and the concentration of N_2O produced.It was found that the catalytic activity order of the single-element oxide is:CuO>Fe_2O_3≈Cr_2O_3> MnO_2>CeO_2>NiO.Cu-Mn-O is more active than CuO,and Cu-Fe-O is more active than Cu-Mn-O and Cu-Cr-O for NO+CO reaction.This study shows that the addition of Ce in supported Cu-M-O can promote their catalytic activities Jot the topic reaction,which makes the reaction of 2NO+CO→N_2O+CO_2 fast,and N_2O is an intermediate compound produced during NO+CO reaction.
基金Open Project of Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake,Grant Number HZHLAB2201.
文摘Carbon monoxide(CO)and nitric oxide(NO)are signal molecules that enhance plant adaptation to environmental stimuli.Auxin is an essential phytohormone for plant growth and development.CO and NO play crucial roles in modulating the plant’s response to iron deficiency.Iron deficiency leads to an increase in the activity of heme oxygenase(HO)and the subsequent generation of CO.Additionally,it alters the polar subcellular distribution of Pin-Formed 1(PIN1)proteins,resulting in enhanced auxin transport.This alteration,in turn,leads to an increase in NO accumulation.Furthermore,iron deficiency enhances the activity of ferric chelate reductase(FCR),as well as the expression of the Fer-like iron deficiency-induced transcription factor 1(FIT)and the ferric reduction oxidase 2(FRO2)genes in plant roots.Overexpression of the long hypocotyl 1(HY1)gene,which encodes heme oxygenase,or the CO donor treatment resulted in enhanced basipetal auxin transport,higher FCR activity,and the expression of FIT and FRO2 genes under Fe deficiency.Here,a potential mechanism is proposed:CO and NO interact with auxin to address iron deficiency stress.CO alters auxin transport,enhancing its accumulation in roots and up-regulating key iron-related genes like FRO2 and IRT1.Elevated auxin levels affect NO signaling,leading to greater sensitivity in root development.This interplay promotes FCR activity,which is crucial for iron absorption.Together,these molecules enhance iron uptake and root growth,revealing a novel aspect of plant physiology in adapting to environmental stress.
基金funded by the National Natural Science Foundation of China,China (Nos.52272303 and 52073212)the General Program of Municipal Natural Science Foundation of Tianjin,China (Nos.17JCYBJC22700 and 17JCYBJC17000)the State Scholarship Fund of China Scholarship Council,China (Nos.201709345012 and 201706255009)。
文摘The global energy-related CO_(2) emissions have rapidly increased as the world economy heavily relied on fossil fuels.This paper explores the pressing challenge of CO_(2) emissions and highlights the role of porous metal oxide materials in the electrocatalytic reduction of CO_(2)(CO_(2)RR).The focus is on the development of robust and selective catalysts,particularly metal and metal-oxide-based materials.Porous metal oxides offer high surface area,enhancing the accessibility to active sites and improving reaction kinetics.The tunability of these materials allows for tailored catalytic behavior,targeting optimized reaction mechanisms for CO_(2)RR.The work also discusses the various synthesis strategies and identifies key structural and compositional features,addressing challenges like high overpotential,poor selectivity,and low stability.Based on these insights,we suggest avenues for future research on porous metal oxide materials for electrochemical CO_(2) reduction.
基金supported by the Russian Science Foundation(grant No.22-19-00037),https://rscf.ru/project/22-19-00037/.
文摘The hydrothermal synthesis of In_(2)O_(3)and CeO_(2)–In_(2)O_(3)is investigated as well as the properties of sensor layers based on these compounds.During the synthesis of In_(2)O_(3),intermediate products In(OH)_(3)and InOOH are formed,which are the precursors of stable cubic(c-In_(2)O_(3))and metastable rhombohedral(rh-In_(2)O_(3))phases,respectively.A transition from c-In_(2)O_(3)to rh-In_(2)O_(3)is observed with the addition of CeO_(2).The introduction of cerium into rh-In_(2)O_(3)results in a decrease in the sensor response to hydrogen,while it increases in composites based on c-In_(2)O_(3).The data on the sensor activity of the composites correlate with XPS results in which CeO_(2)causes a decrease in the concentrations of chemisorbed oxygen and oxygen vacancies in rh-In_(2)O_(3).The reverse situation is observed in composites based on c-In_(2)O_(3).Compared to In_(2)O_(3)and CeO_(2)–In_(2)O_(3)obtained by other methods,the synthesized composites demonstrate maximum response to H_(2)at low temperatures by 70–100℃,and have short response time(0.2–0.5 s),short recovery time(6–7 s),and long-term stability.A model is proposed for the dependence of sensitivity on the direction of electron transfer between In_(2)O_(3)and CeO_(2).
基金supported by the National Natural Science Foundation of China(22178293)the Natural Science Foundation of Fujian Province of China(2022J01022)。
文摘The bioreduction of graphene oxide(GO)using environmentally functional bacteria such as Shewanella represents a green approach to produce reduced graphene oxide(rGO).This process differs from the chemical reduction that involves instantaneous molecular reactions.In bioreduction,the contact of bacterial cells and GO is considered the rate-limiting step.To reveal how the bacteria-GO integration regulates rGO production,the comparative experiments of GO and three Shewanella strains were carried out.Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy,Raman spectroscopy,and atomic force microscopy were used to characterize the reduction degree and the aggregation degree.The results showed that a spontaneous aggregation of GO and Shewanella into the condensed entity occurred within 36 h.A positive linear correlation was established,linking three indexes of the aggregation potential,the bacterial reduction ability,and the reduction degree(ID/IG)comprehensively.
文摘Metal oxide mesocrystals are the alignment of metal oxide nanoparticles building blocks into the ordered superstructure,which have potentially tunable optical,electronic,and electrical properties suitable for practical applications.Herein,we report an effective method for synthesizing mesocrystal zinc oxide nanorods(ZnONRs).The crystal,surface,and internal structures of the zinc oxide mesocrystals were fully characterized.Mesocrystal zinc oxide nanorods/reduced graphene oxide(ZnONRs/rGO)nanocomposite superstructure were synthesized also using the hydrothermal method.The crystal,surface,chemical,and internal structures of the ZnONRs/rGO nanocomposite superstructure were also fully characterized.The optical absorption coefficient,bandgap energy,band structure,and electrical conductivity of the ZnONRs/rGO nanocomposite superstructure were investigated to understand its optoelectronic and electrical properties.Finally,the photoconductivity of the ZnONRs/rGO nanocomposite superstructure was explored to find the possibilities of using this nanocomposite superstructure for ultraviolet(UV)photodetection applications.Finally,we concluded that the ZnONRs/rGO nanocomposite superstructure has high UV sensitivity and is suitable for UV detector applications.
基金supported by the Fundamental Research Funds for the Central Universities(WK9990000102,WK2030000035).
文摘The study of oxide heteroepitaxy has been hindered by the issues of misfit strain and substrate clamping,which impede both the optimization of performance and the acquisition of a fundamental understanding of oxide systems.Recently,however,the development of freestanding oxide membranes has provided a plausible solution to these substrate limitations.Single-crystalline functional oxide films can be released from their substrates without incurring significant damage and can subsequently be transferred to any substrate of choice.This paper discusses recent advancements in the fabrication,adjustable physical properties,and various applications of freestanding oxide perovskite films.First,we present the primary strategies employed for the synthesis and transfer of these freestanding perovskite thin films.Second,we explore the main functionalities observed in freestanding perovskite oxide thin films,with special attention to the tunable functionalities and physical properties of these freestanding perovskite membranes under varying strain states.Next,we encapsulate three representative devices based on freestanding oxide films.Overall,this review highlights the potential of freestanding oxide films for the study of novel functionalities and flexible electronics.
