Microbiologically influenced corrosion(MIC)of steel generates a corrosion product film,which can also be called biomineralization film.It is critical to understand the structure of biomineralization film since it domi...Microbiologically influenced corrosion(MIC)of steel generates a corrosion product film,which can also be called biomineralization film.It is critical to understand the structure of biomineralization film since it dominates the corrosion behavior of metal.In this work,Pseudomonas stutzeri(P.stutzeri)was isolated from seawater,and the biomineralization film caused by marine P.stutzeri was characterized by Transmission electron microscopy(TEM),scanning electron microscopy(SEM),X-ray diffraction(XRD),etc.The mechanistic effects of the biomineralization film on X80 pipeline steel corrosion were also investigated.The results indicate that the minerals are mainly composed of nano FeOand FeOOH,according to TEM and XRD results.The particle sizes of biominerals are below 10 nm.This work also provides an insight strategy to prepare nanomaterials by MIC caused by P.stutzeri.In addition,P.stutzeri can grow well with COas a carbon source and iron as an electron donor.The corrosion rates(CRs)of specimens are closely related to the structure of biomineralization film.The CRs increase with the decrease of initial cell concentration.P.stutzeri with an initial concentration of 10~7 cells/mL can promote the formation of a compact biomineralization film with a thickness of 145.8±4.8μm,leading to corrosion inhibition with a CR of 0.058±0.008 mm/y.But some corrosion pits can be observed due to the formation of small anodes.Electrochemical impedance spectroscopy(EIS)data show higher impedance values and two time-constants,which imply the formation of a compact biomineralization film.展开更多
The corrosion and inhibition effect of magnesium-based rare-earth containing alloy Mg-10Gd-3Y-0.5Zr (GW103) was studied in an ethylene glycol (EG) solution mixed with organic inhibitors. The inhibition efficiencies of...The corrosion and inhibition effect of magnesium-based rare-earth containing alloy Mg-10Gd-3Y-0.5Zr (GW103) was studied in an ethylene glycol (EG) solution mixed with organic inhibitors. The inhibition efficiencies of piperazine and pyrazine inhibitors on the corrosion of GW103 were compared by means of potentiodynamic polarization curve, electrochemical impedance spectroscopy (EIS) and weight loss measurements. It was found that the corrosion process of GW103 alloy in EG solution was hindered by these two inhibitors and the inhibition of pyrazine was more effective than that of piperazine. It was implied that pyrazine could be an effective inhibitor for GW103 in an ethylene glycol coolant solution.展开更多
In this work,we open an avenue toward rational design of potential efficient catalysts for sustainable ammonia synthesis through composition engineering strategy by exploiting the synergistic effects among the active ...In this work,we open an avenue toward rational design of potential efficient catalysts for sustainable ammonia synthesis through composition engineering strategy by exploiting the synergistic effects among the active sites as exemplified by diatomic metals anchored graphdiyne via the combination of hierarchical high-throughput screening,first-principles calculations,and molecular dynamics simulations.Totally 43 highly efficient catalysts feature ultralow onset potentials(|U_(onset)|≤0.40 V)with Rh-Hf and Rh-Ta showing negligible onset potentials of 0 and-0.04 V,respectively.Extremely high catalytic activities of Rh-Hf and Rh-Ta can be ascribed to the synergistic effects.When forming heteronuclears,the combinations of relatively weak(such as Rh)and relatively strong(such as Hf or Ta)components usually lead to the optimal strengths of adsorption Gibbs free energies of reaction intermediates.The origin can be ascribed to the mediate d-band centers of Rh-Hf and Rh-Ta,which lead to the optimal adsorption strengths of intermediates,thereby bringing the high catalytic activities.Our work provides a new and general strategy toward the architecture of highly efficient catalysts not only for electrocatalytic nitrogen reduction reaction(eNRR)but also for other important reactions.We expect that our work will boost both experimental and theoretical efforts in this direction.展开更多
Polycatenane gels have attracted extensive attention due to their high degree of freedom and mobility.However,the syntheses of poly[2]catenane gels reported to date all rely on the polymer as the backbone.Herein,we pr...Polycatenane gels have attracted extensive attention due to their high degree of freedom and mobility.However,the syntheses of poly[2]catenane gels reported to date all rely on the polymer as the backbone.Herein,we prepared poly[2]catenane gels based on entirely sequential assembly of small molecules.Monomer M1 with two unclosed rings was first prepared,which self-assembled to form supramolecular polymers(SPs)via hydrogen bonding andπ-πinteractions.Upon adding small molecule monomers M2 and M3 with aldehyde groups,ring closing of SPs occurred because the amino groups in the SPs reacted with M2 to form imine bonds.In addition,M3,which had twice the number of aldehyde groups as M2,enabled SPs to ring-close,causing the proceeding of crosslinking process at the same time.Thus linear SPs were transformed into poly[2]catenane gel networks.Due to the presence of hydrogen bonds in the poly[2]catenane gel,the gel also possessed stimulus responsiveness and self-healing properties.展开更多
A pyrimidine derivative,6-phenyl-2-thiouracil(PT),was synthesized for developing a corrosion inhibitor(CI)applied in the protection of the nickel−aluminum bronze(NAB)in seawater.The anti-corrosion effect of PT was eva...A pyrimidine derivative,6-phenyl-2-thiouracil(PT),was synthesized for developing a corrosion inhibitor(CI)applied in the protection of the nickel−aluminum bronze(NAB)in seawater.The anti-corrosion effect of PT was evaluated by the mass loss experiment,electrochemical tests and surface analysis.The results show that PT exhibits excellent inhibition performance and the maximum inhibition efficiency of PT reaches 99.6%.The interaction mechanism was investigated through X-ray photoelectron spectroscopy(XPS)and molecule dynamics simulation based on the density functional theory(DFT).The S-Cu,Al-N and Cu-N bonds are formed by the chemical interactions,leading to the adsorption of PT on the NAB surface.The diffusion of corrosive species is hindered considerably by the protective PT film with composition of(PT-Cu)_(ads)and(PT-Al)_(ads)on the PT/NAB interface.The degree of suppression is increased with the addition of more PT molecules.展开更多
The corrosion inhibition effect of Capsella bursa-pastoris extracts(CBE) for Q235 carbon steels in 1 mol·L-1hydrochloric acid solution was studied using electrochemical methods, environmental scanning electron mi...The corrosion inhibition effect of Capsella bursa-pastoris extracts(CBE) for Q235 carbon steels in 1 mol·L-1hydrochloric acid solution was studied using electrochemical methods, environmental scanning electron microscopy(SEM) and Raman microscopy analysis. The polarization plots indicate that CBE serves as an effective, mixedtype inhibitor. Linear polarization resistance shows that increasing CBE concentration and temperature results in increased inhibition ef ficiency. The highest inhibition ef ficiency can reach 97% when adding 60 mg·L-1CBE,which is better than some reported plant extracts under the similar environment. The adsorption of CBE molecules is found to obey the Langmuir adsorption isotherm. Some thermodynamic and kinetic parameters for the adsorption process, such as the adsorption equilibrium constant(K), free energy of adsorption(ΔG ads), activation energy of corrosion reaction(E a) and the heat of adsorption(Q ads), are calculated and discussed. SEM and Raman microscopy analysis also demonstrate the formation of a CBE inhibition film on the metal surface.展开更多
Polypropylene（PP）/ethylene-octene copolymer（POE） blends were prepared with a twin-screw extruder.Their dynamic mechanical behavior were systematically investigated.The results show that PP/POE blends are heterogen...Polypropylene（PP）/ethylene-octene copolymer（POE） blends were prepared with a twin-screw extruder.Their dynamic mechanical behavior were systematically investigated.The results show that PP/POE blends are heterogeneities with a partial compatible two-phase structure,the glass transition temperature of PP phases in the blends tends to shift towards high temperature with increasing the POE content,and the glass transition temperature of POE phases shifts towards the low temperature with increasing the PP content.The Kerner＇s dispersed phase model and co-continuous phase model can reasonably predict the visco-elasticity of PP/POE blends with different compositions.Additionally,the morphological structure of the blends can be estimated via comparing the predicted DMA behavior with the experimental data.展开更多
We for the first time systematically studied the structures and electrochemical nitrogen reduction reaction properties of two-dimensional single transition-metal anchored square tetracyanoquinodimethane monolayers(lab...We for the first time systematically studied the structures and electrochemical nitrogen reduction reaction properties of two-dimensional single transition-metal anchored square tetracyanoquinodimethane monolayers(labeled as:TM-sTCNQ,TM=3d,4d,5d series transition metals)by employing density functional theory method.Through highthroughput screenings and full reaction path researches,two promising electrochemical nitrogen reduction reaction catalysts Nb-sTCNQ and MosTCNQ have been obtained.The nitrogen reduction reaction onset potential on Nb-sTCNQ is as low as−0.48 V.Furthermore,the Nb-sTCNQ catalyst can quickly desorb NH3 produced with a free energy of 0.65 eV,giving Nb-sTCNQ excellent catalytic cycle performance.The high catalytic activity of the two materials might be attributed to the effective charge transfer between the active center and adsorbed N_(2),which enables the active center to adsorb and activate inert N_(2) molecules well,and the reduction processes require small energy input(i.e.,the maximum free energy changes are small).This work provides insights for finding highly efficient,stable,and low-cost nitrogen reduction reaction electrocatalysts.We hope our results can promote further experimental and theoretical research of this field.展开更多
Organometallic nanosheets are a versatile platform for design of efficient electrocatalyst materials due to their high surface area and uniform dispersion of metal active sites.In this paper,we systematically investig...Organometallic nanosheets are a versatile platform for design of efficient electrocatalyst materials due to their high surface area and uniform dispersion of metal active sites.In this paper,we systematically investigate the electrocatalytic performance of the first transition metal series TM3–C12S12 monolayers on CO2 using spin-polarized density functional theory.The calculations show that M3–C12S12 exhibits excellent catalytic activity and selectivity in the catalytic reduction in CO2.The main reduction products of Sc,Ti,and Cr are CH4.V,Mn,Fe and Zn mainly produce HCOOH,and Co produces HCHO,while CO is the main product for Ni and Cu.For Sc,Ti,and Cr,the overpotentials are>0.7 V,while for V,Mn,Fe,Co,Ni,Cu,Zn,the overpotentials are very low and range from 0.27 to 0.47 V.Therefore,our results indicate that many of the M3–C12S12 monolayers are expected to be excellent and efficient CO2 reduction catalysts.展开更多
Surface treatment of glass bead(GB) was carried out by using γ-glycidoxypropyltrimethoxy silane(GPTES) and γ-methacryloxypropyltrimethoxy silane(MPTMS) as coupling agents,respectively.The steady viscosity and yield ...Surface treatment of glass bead(GB) was carried out by using γ-glycidoxypropyltrimethoxy silane(GPTES) and γ-methacryloxypropyltrimethoxy silane(MPTMS) as coupling agents,respectively.The steady viscosity and yield stress of the GB/hydroxyl terminated polybutadiene(HTPB) suspensions were determined by Brookfield R/S rheometer.The effect of surface treatment on the viscosity and yield stress of GB/HTPB suspension was investigated.The results indicate that the viscosity of the pristine GB/HTPB suspension increases with increasing GB,and the relationship between its viscosity and volume fraction of GB depends on the shear rate.The modification of GB by MPTMS changes the viscosity of the MPTMS@GB/HTPB suspension,and its viscosity is the minimum at the MPTMS dosage of 0.3 g per 1 g GB.Additionally,the modification of GB by MPTMS increases the yield stress of the GB/HTPB suspension,and its yield stress is the maximum at the MPTMS dosage of 0.1 g per 1 g GB.The GPTES modified GB/HTPB suspension behaves lower viscosity and weaker shear thinning than the MPTMS modified GB/HTPB suspension within the range of experimental shear rate.展开更多
Photo-responsive cholesteric liquid crystals(CLCs)have attracted much attention in recent years due to their wide applications in filters,tun able optical lasers,dyn amic display devices,etc.However,UV light is usuall...Photo-responsive cholesteric liquid crystals(CLCs)have attracted much attention in recent years due to their wide applications in filters,tun able optical lasers,dyn amic display devices,etc.However,UV light is usually used as the exter nal stimulus source,which is not envir on ment-frie ndly enough.On the other hand,the mecha nical properties of CLCs are not strong eno ugh for these practical applications.Therefore,it still remains a challenge to endow the CLCs with visible light response and high mechanical properties at the same time.Herein,an axially chiral tetra-fluorinated binaphthyl azobenzene gelator(S-4F-AG)is synthesized.Upon 550 and 450 nm light irradiations,S-4F-AG exhibits excellent photo-switchable behaviors.Notably,the maximum con tent of c/s-isomer and its half-life are as high as 35%and 89 h in acet on itrile,respectively.A self-supporting CLC physical gel with a storage modulus around 104 Pa can be obtained when 3wt%S-4F-AG and 12wt%binaphthyl azobenzene derivative(dopant 2)are co-doped into a nematic LC host P0616A.This CLC physical gel exhibits a temperature-driven blue,green,and red reflection colors reversibly.Importantly,such three primary RGB colors can also be realized by adjusting the exposure time of 550 nm green light.This work lays a solid foundation for the applications ranging from information storage to high-tech anticounterfeit.展开更多
In this work,through the self-developed setup for in situ electrochemical tests,the corrosion behavior of 13 Cr stainless steel under the combined effect of stress and crevice in high pressure CO_(2)/O_(2)environment ...In this work,through the self-developed setup for in situ electrochemical tests,the corrosion behavior of 13 Cr stainless steel under the combined effect of stress and crevice in high pressure CO_(2)/O_(2)environment was investigated.The results show that 13 Cr stainless steel presents a self-passivation state.Under the action of stress,the anodic dissolution process of steel inside crevice is expedited.There is a galvanic effect between the stressed steel inside crevice and the unstressed steel outside crevice.The applied stress reduces the induction stage of crevice corrosion and induces a larger galvanic current,i.e.,the applied stress promotes the development of crevice corrosion.Meanwhile,adding 0.1 MPa O_(2)is conducive to forming a more stable passive film but causes a greater galvanic effect.展开更多
Vitamin B_(12)(macrocyclic cobalamin)has been recently reported to be capable of electrochemically catalyzing water oxidation in a neutral phosphate buffer solution.In this work,density functional calculations were em...Vitamin B_(12)(macrocyclic cobalamin)has been recently reported to be capable of electrochemically catalyzing water oxidation in a neutral phosphate buffer solution.In this work,density functional calculations were employed to elucidate the water oxidation mechanism catalyzed by vitamin B_(12).The calculations showed that the catalytic cycle starts from the L·-Co^(Ⅱ)-OH_(2)complex 1.A proton-coupled electron transfer process then leads to the formation of a L^(·)-Co^(Ⅲ)-OH complex 2,followed by another proton-coupled electron transfer event to afford a corrin ligand radical cation intermediate 3(L^(·)-Co^(Ⅲ)-O^(·)).The redox non-innocent nature of the corrin ligand plays an essential role in the oxidation process.3 is capable of triggering the O-O bond formation via a water nucleophilic attack mechanism,in which a hydrophosphate dianion functions as a base to accept a proton from the water nucleophile.A dioxygen molecule is released after the oxidation of the Co^(Ⅲ)-OOH intermediate.The rate-determining step was calculated to be the O-O bond formation with a total barrier of 16.5 kcal/mol.While the use of water molecules as the proton acceptor was found to be less feasible for the O-O bond formation,with a barrier of 31.2 kcal/mol,further highlighting the crucial of phosphate in water oxidation.展开更多
Developing high-performance catalysts for oxygen reduction reaction to replace costly platinum-based materials is of great importance but still confronted with challenges.Herein,a kind of supported palladium liquid me...Developing high-performance catalysts for oxygen reduction reaction to replace costly platinum-based materials is of great importance but still confronted with challenges.Herein,a kind of supported palladium liquid metal catalyst,which is prepared by galvanic replacement,surpasses commercial Pt/C and Pd/C in oxygen reduction catalysis with a higher half-wave potential of 0.92 V,mass activity of 1.85 A/mgPd at 0.90 V,and superior durability.The liquid metal support can both optimize the electronic structures of Pd sites and guarantee the dispersion of Pd atoms,which explains the enhanced activity and durability,respectively.This work opens an avenue for rational design of catalysts.展开更多
Supramolecular polymers,as a type of dynamic polymers,are subordinate to the interdisciplinary field of polymer chemistry and supramolecular chemistry,whose development has greatly promoted the prosperity of new mater...Supramolecular polymers,as a type of dynamic polymers,are subordinate to the interdisciplinary field of polymer chemistry and supramolecular chemistry,whose development has greatly promoted the prosperity of new materials.Notably,molecular weight is one of the most important parameters of supramolecular polymers,which affects the physical/chemical properties and processing applications of materials.Developing new methods for characterizing the molecular weight of supramolecular polymers is crucial for advancing the development of supramolecular polymers.In this review,we elaborate and summarize three strategies for characterizing the molecular weight of supramolecular polymers that recently reported by our research group according to the characteristics of supramolecular polymers,including(1)the molecular weight distinction corresponding to variable fluorescence colors,(2)matching different molecular weights with different fluorescence lifetime,(3)transforming supramolecular polymers into mechanically interlocked polymers or covalent polymers.Besides,we also discuss the limitations of current methods for characterizing supramolecular polymers.We hope that this review can promote the development of supramolecular polymers and significantly inspire to exploit new methods to characterizing molecular weight of supramolecular polymers.展开更多
Structured block copolymer(BCP) particles have gained increasing attention due to their potential applications in separation,catalysis, controlled release, and other fields. Three-dimensional(3D) confined assembly has...Structured block copolymer(BCP) particles have gained increasing attention due to their potential applications in separation,catalysis, controlled release, and other fields. Three-dimensional(3D) confined assembly has been proved as a facile yet robust approach for generating BCP particles with controllable shapes and internal structures. In this feature article, we summarized the preparation of structured polymeric particles through 3D confined self-assembly of BCPs. The effects of interfacial interactions, degree of confinement,and additives on the shape and internal structure of BCP microparticles were comprehensively discussed. In addition, we highlighted the recent progress in using disassembly as a route to synthesize colloidal particles with unique structures. Two strategies were introduced in this part:(a) disassembling the discrete domains resulted in mesoporous microparticles;(b) disassembling the continuous domains led to the dissociation of microparticles into micelle-like nano-objects. The applications of the structured colloidal particles in photonic crystals,controlled release, and directed growth of inorganic materials were also presented. Finally, we discussed the current challenges and future opportunities in this promising area.展开更多
An efficient preparation and local coordination environment regulation of isolated single-atom sites catalysts(ISASC)for improved activity is still challenging.Herein,we develop a solid phase thermal diffusion strateg...An efficient preparation and local coordination environment regulation of isolated single-atom sites catalysts(ISASC)for improved activity is still challenging.Herein,we develop a solid phase thermal diffusion strategy to synthesize Mn ISASC on highly uniform nitrogen-doped carbon nanotubes by employing MnO_(2) nanowires@ZIF-8 core-shell structure.Under high-temperature,the Mn species break free from core-MnO_(2) lattice,which will be trapped by carbon defects derived from shell-ZIF-8 carbonization,and immobilized within carbon substrate.Furthermore,the poly-dispersed Mn sites with two nitrogen-coordinated centers can be controllably renovated into four-nitrogen-coordinated Mn sites using NH3 treatment technology.Both experimental and computational investigations indicate that the symmetric coordinated Mn sites manifest outstanding oxygen reduction activity and superior stability in alkaline and acidic solutions.This work not only provides efficient way to regulate the coordination structure of ISASC to improve catalytic performance but also paves the way to reveal its significant promise for commercial application.展开更多
Five-coordinate neutral Cu(Ⅲ)complexes have long been considered as the key intermediates in copper-mediated/catalyzed arene trifluoromethylative reactions,but the identity of these complexes remains elusive.Herein,w...Five-coordinate neutral Cu(Ⅲ)complexes have long been considered as the key intermediates in copper-mediated/catalyzed arene trifluoromethylative reactions,but the identity of these complexes remains elusive.Herein,we reported,for the first time,the preparation and characterization of these putative complexes[(bpy)Cu(CF_(3))_(2)(C_(6)F_(4)R)]and investigation of their C(sp^(2))-CF_(3) bond-forming reductive elimination.Our mechanistic studies including kinetic studies,the effect of temperature and solvents,the effect of the para-substitution of the ligand as well as DFT calculations suggest that C(sp^(2))-CF_(3) reductive elimination process proceeds via synchronous bond-breaking/bond-forming process.展开更多
Films formed with nanosized nickel particles on teflon surface were prepared by means of catalyst enhanced chemical vapor deposition （CECVD） with Ni（dmg）2, Ni（acac）2, Ni（hfac）2, Ni（TMHD）2, and Ni（cp）2 as p...Films formed with nanosized nickel particles on teflon surface were prepared by means of catalyst enhanced chemical vapor deposition （CECVD） with Ni（dmg）2, Ni（acac）2, Ni（hfac）2, Ni（TMHD）2, and Ni（cp）2 as precursors, and complexes Pd（hfac）2, PdC12 and Pd（η^3-2-methylallyl）acac as catalyst under cartier gas （H2）. The film growth rate depends on the precursors and substrate temperature. The chemical value, purity and surface morphology of the Ni particle films were characterized by X-ray photoelectron spectroscopy （XPS） and scanning electron microscopy （SEM）. The films obtained were shiny with silvery color, and consisted of grains with a particle size of 50-140 nm. The Ni was metallic of which the purity was about 90%-95% from XPS analysis. SEM micrograph showed that the film had good morphology.展开更多
Life,defined as the specific form of substance,is an integration of aggregates at various scales,ranging from single molecules to tissues.However,these building blocks of common aggregates are usually recognized as co...Life,defined as the specific form of substance,is an integration of aggregates at various scales,ranging from single molecules to tissues.However,these building blocks of common aggregates are usually recognized as confining at the microscopic level,while there are few studies focusing on macroscopic building blocks for aggregates.Fluorescent gels,as the important macroscopic building blocks,are drawing researchers’attention on account of their extraordinary fluorescence as well as soft material properties.Inspired by nature,fluorescent gels can be aggregated through interfacial adhesion.According to the driving forces for interfacial adhesion,a series of aggregates of fluorescent gels(AFGs)was summarized,including H-bond,metal coordinations,host-vip interactions,hydrophobic interactions,electrostatic interactions,dynamic covalent bonds as well as multiple driving forces.These AFGs own dynamic assembled behaviors and rich stimuli responsiveness,which could be applied to information storage,sensing,biomedical systems,and so on.The authors anticipate this review can accelerate the development of aggregate science,especially based on macroscopic building blocks.展开更多
基金supported by the National Natural Science Foundation of China(No.51901253)Fundamental Research Funds for the Central Universities(No.19lgzd18)+2 种基金Guangdong Basic and Applied Basic Research Foundation(No.2019A1515011135)the Open Project Program of Beijing Key Laboratory of Pipeline Critical Technology and Equipment for Deepwater Oil&Gas Development(No.BIPT201904)the Open Project Program of Hubei Key Laboratory of Materials Chemistry and Service Failure(No.2020MCF02)。
文摘Microbiologically influenced corrosion(MIC)of steel generates a corrosion product film,which can also be called biomineralization film.It is critical to understand the structure of biomineralization film since it dominates the corrosion behavior of metal.In this work,Pseudomonas stutzeri(P.stutzeri)was isolated from seawater,and the biomineralization film caused by marine P.stutzeri was characterized by Transmission electron microscopy(TEM),scanning electron microscopy(SEM),X-ray diffraction(XRD),etc.The mechanistic effects of the biomineralization film on X80 pipeline steel corrosion were also investigated.The results indicate that the minerals are mainly composed of nano FeOand FeOOH,according to TEM and XRD results.The particle sizes of biominerals are below 10 nm.This work also provides an insight strategy to prepare nanomaterials by MIC caused by P.stutzeri.In addition,P.stutzeri can grow well with COas a carbon source and iron as an electron donor.The corrosion rates(CRs)of specimens are closely related to the structure of biomineralization film.The CRs increase with the decrease of initial cell concentration.P.stutzeri with an initial concentration of 10~7 cells/mL can promote the formation of a compact biomineralization film with a thickness of 145.8±4.8μm,leading to corrosion inhibition with a CR of 0.058±0.008 mm/y.But some corrosion pits can be observed due to the formation of small anodes.Electrochemical impedance spectroscopy(EIS)data show higher impedance values and two time-constants,which imply the formation of a compact biomineralization film.
文摘The corrosion and inhibition effect of magnesium-based rare-earth containing alloy Mg-10Gd-3Y-0.5Zr (GW103) was studied in an ethylene glycol (EG) solution mixed with organic inhibitors. The inhibition efficiencies of piperazine and pyrazine inhibitors on the corrosion of GW103 were compared by means of potentiodynamic polarization curve, electrochemical impedance spectroscopy (EIS) and weight loss measurements. It was found that the corrosion process of GW103 alloy in EG solution was hindered by these two inhibitors and the inhibition of pyrazine was more effective than that of piperazine. It was implied that pyrazine could be an effective inhibitor for GW103 in an ethylene glycol coolant solution.
基金support from the National Natural Science Foundation of China(22073033,21873032,21673087,21903032)startup fund(2006013118 and 3004013105)from Huazhong University of Science and Technology+1 种基金the Fundamental Research Funds for the Central Universities(2019kfyRCPY116)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003)
文摘In this work,we open an avenue toward rational design of potential efficient catalysts for sustainable ammonia synthesis through composition engineering strategy by exploiting the synergistic effects among the active sites as exemplified by diatomic metals anchored graphdiyne via the combination of hierarchical high-throughput screening,first-principles calculations,and molecular dynamics simulations.Totally 43 highly efficient catalysts feature ultralow onset potentials(|U_(onset)|≤0.40 V)with Rh-Hf and Rh-Ta showing negligible onset potentials of 0 and-0.04 V,respectively.Extremely high catalytic activities of Rh-Hf and Rh-Ta can be ascribed to the synergistic effects.When forming heteronuclears,the combinations of relatively weak(such as Rh)and relatively strong(such as Hf or Ta)components usually lead to the optimal strengths of adsorption Gibbs free energies of reaction intermediates.The origin can be ascribed to the mediate d-band centers of Rh-Hf and Rh-Ta,which lead to the optimal adsorption strengths of intermediates,thereby bringing the high catalytic activities.Our work provides a new and general strategy toward the architecture of highly efficient catalysts not only for electrocatalytic nitrogen reduction reaction(eNRR)but also for other important reactions.We expect that our work will boost both experimental and theoretical efforts in this direction.
基金X.Ji acknowledges funding from the National Natural Science Foundation of China(No.22001087)X.Ji also appreciates the support from the Huazhong University of Science and Technology,where he is being supported by Fundamental Research Funds for the Central Universities(Grant 2020kfyXJJS013)X.Ji appreciates support from the Interdisciplinary Research Program of HUST(2023JCYJ013).
文摘Polycatenane gels have attracted extensive attention due to their high degree of freedom and mobility.However,the syntheses of poly[2]catenane gels reported to date all rely on the polymer as the backbone.Herein,we prepared poly[2]catenane gels based on entirely sequential assembly of small molecules.Monomer M1 with two unclosed rings was first prepared,which self-assembled to form supramolecular polymers(SPs)via hydrogen bonding andπ-πinteractions.Upon adding small molecule monomers M2 and M3 with aldehyde groups,ring closing of SPs occurred because the amino groups in the SPs reacted with M2 to form imine bonds.In addition,M3,which had twice the number of aldehyde groups as M2,enabled SPs to ring-close,causing the proceeding of crosslinking process at the same time.Thus linear SPs were transformed into poly[2]catenane gel networks.Due to the presence of hydrogen bonds in the poly[2]catenane gel,the gel also possessed stimulus responsiveness and self-healing properties.
基金supported by the National Natural Science Foundation of China(No.52171069).
文摘A pyrimidine derivative,6-phenyl-2-thiouracil(PT),was synthesized for developing a corrosion inhibitor(CI)applied in the protection of the nickel−aluminum bronze(NAB)in seawater.The anti-corrosion effect of PT was evaluated by the mass loss experiment,electrochemical tests and surface analysis.The results show that PT exhibits excellent inhibition performance and the maximum inhibition efficiency of PT reaches 99.6%.The interaction mechanism was investigated through X-ray photoelectron spectroscopy(XPS)and molecule dynamics simulation based on the density functional theory(DFT).The S-Cu,Al-N and Cu-N bonds are formed by the chemical interactions,leading to the adsorption of PT on the NAB surface.The diffusion of corrosive species is hindered considerably by the protective PT film with composition of(PT-Cu)_(ads)and(PT-Al)_(ads)on the PT/NAB interface.The degree of suppression is increased with the addition of more PT molecules.
基金Supported by the National Natural Science Foundation of China(51101066)
文摘The corrosion inhibition effect of Capsella bursa-pastoris extracts(CBE) for Q235 carbon steels in 1 mol·L-1hydrochloric acid solution was studied using electrochemical methods, environmental scanning electron microscopy(SEM) and Raman microscopy analysis. The polarization plots indicate that CBE serves as an effective, mixedtype inhibitor. Linear polarization resistance shows that increasing CBE concentration and temperature results in increased inhibition ef ficiency. The highest inhibition ef ficiency can reach 97% when adding 60 mg·L-1CBE,which is better than some reported plant extracts under the similar environment. The adsorption of CBE molecules is found to obey the Langmuir adsorption isotherm. Some thermodynamic and kinetic parameters for the adsorption process, such as the adsorption equilibrium constant(K), free energy of adsorption(ΔG ads), activation energy of corrosion reaction(E a) and the heat of adsorption(Q ads), are calculated and discussed. SEM and Raman microscopy analysis also demonstrate the formation of a CBE inhibition film on the metal surface.
基金Supported by the National Natural Science Foundation of China(No.20490220)Open Fund of State Key Laboratory of Plastic Forming Simulation and Die & Mould Technology,China(No.05-10)+1 种基金Open Fund of Hubei Key Laboratory of Materials Chemistry and Service FailureProgram for New Century Excellent Talents in Universities of China(No.NCET-05-0640)
文摘Polypropylene（PP）/ethylene-octene copolymer（POE） blends were prepared with a twin-screw extruder.Their dynamic mechanical behavior were systematically investigated.The results show that PP/POE blends are heterogeneities with a partial compatible two-phase structure,the glass transition temperature of PP phases in the blends tends to shift towards high temperature with increasing the POE content,and the glass transition temperature of POE phases shifts towards the low temperature with increasing the PP content.The Kerner＇s dispersed phase model and co-continuous phase model can reasonably predict the visco-elasticity of PP/POE blends with different compositions.Additionally,the morphological structure of the blends can be estimated via comparing the predicted DMA behavior with the experimental data.
基金support from the National Natural Science Foundation of China(22073033,21873032,21673087,21903032)startup fund(2006013118 and 3004013105)from Huazhong University of Science and Technology+5 种基金the Fundamental Research Funds for the Central Universities(2019kfyRCPY116)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003)support from Guangdong Basic and Applied Basic Research Foundation(2021A1515010382)the computational resources from the computing cluster at the Key Laboratory of Theoretical Chemistry of Environment,Ministry of Education&School of Chemistry,South China Normal UniversityThe work was carried out at the LvLiang Cloud Computing Center of China,and the calculations were performed on TianHe-2The computing work in this paper is supported by the Public Service Platform of High Performance Computing by Network and Computing Center of HUST.
文摘We for the first time systematically studied the structures and electrochemical nitrogen reduction reaction properties of two-dimensional single transition-metal anchored square tetracyanoquinodimethane monolayers(labeled as:TM-sTCNQ,TM=3d,4d,5d series transition metals)by employing density functional theory method.Through highthroughput screenings and full reaction path researches,two promising electrochemical nitrogen reduction reaction catalysts Nb-sTCNQ and MosTCNQ have been obtained.The nitrogen reduction reaction onset potential on Nb-sTCNQ is as low as−0.48 V.Furthermore,the Nb-sTCNQ catalyst can quickly desorb NH3 produced with a free energy of 0.65 eV,giving Nb-sTCNQ excellent catalytic cycle performance.The high catalytic activity of the two materials might be attributed to the effective charge transfer between the active center and adsorbed N_(2),which enables the active center to adsorb and activate inert N_(2) molecules well,and the reduction processes require small energy input(i.e.,the maximum free energy changes are small).This work provides insights for finding highly efficient,stable,and low-cost nitrogen reduction reaction electrocatalysts.We hope our results can promote further experimental and theoretical research of this field.
基金support from the National Natural Science Foundation of China(21673087 and 21873032)startup fund(2006013118 and 3004013105)from Huazhong University of Science and Technologythe Fundamental Research Funds for the Central Universities(2019kfy R CPY116)
文摘Organometallic nanosheets are a versatile platform for design of efficient electrocatalyst materials due to their high surface area and uniform dispersion of metal active sites.In this paper,we systematically investigate the electrocatalytic performance of the first transition metal series TM3–C12S12 monolayers on CO2 using spin-polarized density functional theory.The calculations show that M3–C12S12 exhibits excellent catalytic activity and selectivity in the catalytic reduction in CO2.The main reduction products of Sc,Ti,and Cr are CH4.V,Mn,Fe and Zn mainly produce HCOOH,and Co produces HCHO,while CO is the main product for Ni and Cu.For Sc,Ti,and Cr,the overpotentials are>0.7 V,while for V,Mn,Fe,Co,Ni,Cu,Zn,the overpotentials are very low and range from 0.27 to 0.47 V.Therefore,our results indicate that many of the M3–C12S12 monolayers are expected to be excellent and efficient CO2 reduction catalysts.
文摘Surface treatment of glass bead(GB) was carried out by using γ-glycidoxypropyltrimethoxy silane(GPTES) and γ-methacryloxypropyltrimethoxy silane(MPTMS) as coupling agents,respectively.The steady viscosity and yield stress of the GB/hydroxyl terminated polybutadiene(HTPB) suspensions were determined by Brookfield R/S rheometer.The effect of surface treatment on the viscosity and yield stress of GB/HTPB suspension was investigated.The results indicate that the viscosity of the pristine GB/HTPB suspension increases with increasing GB,and the relationship between its viscosity and volume fraction of GB depends on the shear rate.The modification of GB by MPTMS changes the viscosity of the MPTMS@GB/HTPB suspension,and its viscosity is the minimum at the MPTMS dosage of 0.3 g per 1 g GB.Additionally,the modification of GB by MPTMS increases the yield stress of the GB/HTPB suspension,and its yield stress is the maximum at the MPTMS dosage of 0.1 g per 1 g GB.The GPTES modified GB/HTPB suspension behaves lower viscosity and weaker shear thinning than the MPTMS modified GB/HTPB suspension within the range of experimental shear rate.
文摘Photo-responsive cholesteric liquid crystals(CLCs)have attracted much attention in recent years due to their wide applications in filters,tun able optical lasers,dyn amic display devices,etc.However,UV light is usually used as the exter nal stimulus source,which is not envir on ment-frie ndly enough.On the other hand,the mecha nical properties of CLCs are not strong eno ugh for these practical applications.Therefore,it still remains a challenge to endow the CLCs with visible light response and high mechanical properties at the same time.Herein,an axially chiral tetra-fluorinated binaphthyl azobenzene gelator(S-4F-AG)is synthesized.Upon 550 and 450 nm light irradiations,S-4F-AG exhibits excellent photo-switchable behaviors.Notably,the maximum con tent of c/s-isomer and its half-life are as high as 35%and 89 h in acet on itrile,respectively.A self-supporting CLC physical gel with a storage modulus around 104 Pa can be obtained when 3wt%S-4F-AG and 12wt%binaphthyl azobenzene derivative(dopant 2)are co-doped into a nematic LC host P0616A.This CLC physical gel exhibits a temperature-driven blue,green,and red reflection colors reversibly.Importantly,such three primary RGB colors can also be realized by adjusting the exposure time of 550 nm green light.This work lays a solid foundation for the applications ranging from information storage to high-tech anticounterfeit.
基金financially supported by the National Natural Science Foundation of China(No.51571097)。
文摘In this work,through the self-developed setup for in situ electrochemical tests,the corrosion behavior of 13 Cr stainless steel under the combined effect of stress and crevice in high pressure CO_(2)/O_(2)environment was investigated.The results show that 13 Cr stainless steel presents a self-passivation state.Under the action of stress,the anodic dissolution process of steel inside crevice is expedited.There is a galvanic effect between the stressed steel inside crevice and the unstressed steel outside crevice.The applied stress reduces the induction stage of crevice corrosion and induces a larger galvanic current,i.e.,the applied stress promotes the development of crevice corrosion.Meanwhile,adding 0.1 MPa O_(2)is conducive to forming a more stable passive film but causes a greater galvanic effect.
基金supported by the National Natural Science Foundation of China(No.21873031)the National Key R&D Program of China(No.2018YFA0903500)。
文摘Vitamin B_(12)(macrocyclic cobalamin)has been recently reported to be capable of electrochemically catalyzing water oxidation in a neutral phosphate buffer solution.In this work,density functional calculations were employed to elucidate the water oxidation mechanism catalyzed by vitamin B_(12).The calculations showed that the catalytic cycle starts from the L·-Co^(Ⅱ)-OH_(2)complex 1.A proton-coupled electron transfer process then leads to the formation of a L^(·)-Co^(Ⅲ)-OH complex 2,followed by another proton-coupled electron transfer event to afford a corrin ligand radical cation intermediate 3(L^(·)-Co^(Ⅲ)-O^(·)).The redox non-innocent nature of the corrin ligand plays an essential role in the oxidation process.3 is capable of triggering the O-O bond formation via a water nucleophilic attack mechanism,in which a hydrophosphate dianion functions as a base to accept a proton from the water nucleophile.A dioxygen molecule is released after the oxidation of the Co^(Ⅲ)-OOH intermediate.The rate-determining step was calculated to be the O-O bond formation with a total barrier of 16.5 kcal/mol.While the use of water molecules as the proton acceptor was found to be less feasible for the O-O bond formation,with a barrier of 31.2 kcal/mol,further highlighting the crucial of phosphate in water oxidation.
基金National Key Research and Development Program of China(No.2021YFE0191700)National Natural Science Foundation of China(Nos.22073033,21873032,21673087,21903032)+5 种基金Natural Science Foundation of Anhui Province,China(No.2108085QB70)Fundamental Research Funds for the Central Universities,China(Nos.WK2060000004,WK2060000021,WK2060000025,KY2060000180,2019kfyRCPY116)Collaborative Innovation Program of Hefei Science Center of CAS(No.2021HSC-CIP002)Natural Science Foundation of Hefei City,China(No.2021044)Startup Fund from Huazhong University of Science and Technology,China(Nos.2006013118,3004013105)Innovation and Talent Recruitment Base of New Energy Chemistry and Device,China(No.B21003).
文摘Developing high-performance catalysts for oxygen reduction reaction to replace costly platinum-based materials is of great importance but still confronted with challenges.Herein,a kind of supported palladium liquid metal catalyst,which is prepared by galvanic replacement,surpasses commercial Pt/C and Pd/C in oxygen reduction catalysis with a higher half-wave potential of 0.92 V,mass activity of 1.85 A/mgPd at 0.90 V,and superior durability.The liquid metal support can both optimize the electronic structures of Pd sites and guarantee the dispersion of Pd atoms,which explains the enhanced activity and durability,respectively.This work opens an avenue for rational design of catalysts.
基金supported by the National Natural Science Foundation of China(No.22001087)supported by Fundamental Research Funds for the Central Universities(No.2020kfy XJJS013)Interdisciplinary Research Program of HUST(No.2023JCYJ013)。
文摘Supramolecular polymers,as a type of dynamic polymers,are subordinate to the interdisciplinary field of polymer chemistry and supramolecular chemistry,whose development has greatly promoted the prosperity of new materials.Notably,molecular weight is one of the most important parameters of supramolecular polymers,which affects the physical/chemical properties and processing applications of materials.Developing new methods for characterizing the molecular weight of supramolecular polymers is crucial for advancing the development of supramolecular polymers.In this review,we elaborate and summarize three strategies for characterizing the molecular weight of supramolecular polymers that recently reported by our research group according to the characteristics of supramolecular polymers,including(1)the molecular weight distinction corresponding to variable fluorescence colors,(2)matching different molecular weights with different fluorescence lifetime,(3)transforming supramolecular polymers into mechanically interlocked polymers or covalent polymers.Besides,we also discuss the limitations of current methods for characterizing supramolecular polymers.We hope that this review can promote the development of supramolecular polymers and significantly inspire to exploit new methods to characterizing molecular weight of supramolecular polymers.
基金financially supported by the National Natural Science Foundation of China (Nos. 51525302 and 51811540404)Program for HUST Academic Frontier Youth Team (No. 2015-01)the Fundamental Research Funds for the Central Universities (No. 2019kfyXJJS077)
文摘Structured block copolymer(BCP) particles have gained increasing attention due to their potential applications in separation,catalysis, controlled release, and other fields. Three-dimensional(3D) confined assembly has been proved as a facile yet robust approach for generating BCP particles with controllable shapes and internal structures. In this feature article, we summarized the preparation of structured polymeric particles through 3D confined self-assembly of BCPs. The effects of interfacial interactions, degree of confinement,and additives on the shape and internal structure of BCP microparticles were comprehensively discussed. In addition, we highlighted the recent progress in using disassembly as a route to synthesize colloidal particles with unique structures. Two strategies were introduced in this part:(a) disassembling the discrete domains resulted in mesoporous microparticles;(b) disassembling the continuous domains led to the dissociation of microparticles into micelle-like nano-objects. The applications of the structured colloidal particles in photonic crystals,controlled release, and directed growth of inorganic materials were also presented. Finally, we discussed the current challenges and future opportunities in this promising area.
基金This work was supported by the National Key R&D Program of China 2017YFA(Nos.0208300 and 0700104)the National Natural Science Foundation of China(Nos.21671180,21802132,22073033,21673087,21873032,and 21903032)+2 种基金startup fund(Nos.2006013118 and 3004013105)from Huazhong University of Science and Technologythe Fundamental Research Funds for the Central Universities(2019kfyRCPY116)the Innovation and Talent Recruitment Base of New Energy Chemistry and Device(B21003).
文摘An efficient preparation and local coordination environment regulation of isolated single-atom sites catalysts(ISASC)for improved activity is still challenging.Herein,we develop a solid phase thermal diffusion strategy to synthesize Mn ISASC on highly uniform nitrogen-doped carbon nanotubes by employing MnO_(2) nanowires@ZIF-8 core-shell structure.Under high-temperature,the Mn species break free from core-MnO_(2) lattice,which will be trapped by carbon defects derived from shell-ZIF-8 carbonization,and immobilized within carbon substrate.Furthermore,the poly-dispersed Mn sites with two nitrogen-coordinated centers can be controllably renovated into four-nitrogen-coordinated Mn sites using NH3 treatment technology.Both experimental and computational investigations indicate that the symmetric coordinated Mn sites manifest outstanding oxygen reduction activity and superior stability in alkaline and acidic solutions.This work not only provides efficient way to regulate the coordination structure of ISASC to improve catalytic performance but also paves the way to reveal its significant promise for commercial application.
基金the financial support from the National Key Research and Development Program of China(No.2021YFF0701700)the National Natural Science Foundation of China(Nos.21625206,22061160465,22122104,21933004 and 22103027).
文摘Five-coordinate neutral Cu(Ⅲ)complexes have long been considered as the key intermediates in copper-mediated/catalyzed arene trifluoromethylative reactions,but the identity of these complexes remains elusive.Herein,we reported,for the first time,the preparation and characterization of these putative complexes[(bpy)Cu(CF_(3))_(2)(C_(6)F_(4)R)]and investigation of their C(sp^(2))-CF_(3) bond-forming reductive elimination.Our mechanistic studies including kinetic studies,the effect of temperature and solvents,the effect of the para-substitution of the ligand as well as DFT calculations suggest that C(sp^(2))-CF_(3) reductive elimination process proceeds via synchronous bond-breaking/bond-forming process.
基金Supported by the National Natural Science Foundation ofChina (40172018, 20275011)
文摘Films formed with nanosized nickel particles on teflon surface were prepared by means of catalyst enhanced chemical vapor deposition （CECVD） with Ni（dmg）2, Ni（acac）2, Ni（hfac）2, Ni（TMHD）2, and Ni（cp）2 as precursors, and complexes Pd（hfac）2, PdC12 and Pd（η^3-2-methylallyl）acac as catalyst under cartier gas （H2）. The film growth rate depends on the precursors and substrate temperature. The chemical value, purity and surface morphology of the Ni particle films were characterized by X-ray photoelectron spectroscopy （XPS） and scanning electron microscopy （SEM）. The films obtained were shiny with silvery color, and consisted of grains with a particle size of 50-140 nm. The Ni was metallic of which the purity was about 90%-95% from XPS analysis. SEM micrograph showed that the film had good morphology.
基金National Natural Science Foundation of China,Grant/Award Number:22001087Fundamental Research Funds for the Central Universities,Grant/Award Number:2020kfyXJJS013+1 种基金Open Fund of Hubei Key Laboratory of Material Chemistry and Service Failure,Huazhong University of Science and Technology,Grant/Award Number:2020MCF08Open Research Fund of Key Laboratory of Material Chemistry for Energy Conversion and Storage,Huazhong University of Science and Technology,Ministry of Education,Grant/Award Number:2021JYBKF01。
文摘Life,defined as the specific form of substance,is an integration of aggregates at various scales,ranging from single molecules to tissues.However,these building blocks of common aggregates are usually recognized as confining at the microscopic level,while there are few studies focusing on macroscopic building blocks for aggregates.Fluorescent gels,as the important macroscopic building blocks,are drawing researchers’attention on account of their extraordinary fluorescence as well as soft material properties.Inspired by nature,fluorescent gels can be aggregated through interfacial adhesion.According to the driving forces for interfacial adhesion,a series of aggregates of fluorescent gels(AFGs)was summarized,including H-bond,metal coordinations,host-vip interactions,hydrophobic interactions,electrostatic interactions,dynamic covalent bonds as well as multiple driving forces.These AFGs own dynamic assembled behaviors and rich stimuli responsiveness,which could be applied to information storage,sensing,biomedical systems,and so on.The authors anticipate this review can accelerate the development of aggregate science,especially based on macroscopic building blocks.
