The unique structure and formation mechanism of medium-entropy alloys(MEAs)generally result in bet-ter comprehensive properties than traditional alloys.However,the strength-ductility trade-offremains a bottleneck,whic...The unique structure and formation mechanism of medium-entropy alloys(MEAs)generally result in bet-ter comprehensive properties than traditional alloys.However,the strength-ductility trade-offremains a bottleneck,which limits their applications.In this study,we designed novel high-performance CrNiCu x MEAs with a heterophase composition by incorporating a Cu-rich phase,and they were fabricated using laser-directed energy deposition(LDED).The results show that synergistic strengthening from multiple phases significantly improved the mechanical properties of the alloys,resulting in a tensile strength of 675 MPa and a ductility of 34.4%,demonstrating an excellent combination of high tensile strength and ductility.The improved mechanical properties of the CrNiCu x medium-entropy alloys are primarily due to the heterophase interfacial strengthening mechanism.In the alloy,numerous semi-coherent and coher-ent interfaces formed between the Cr-rich phase,Cu-rich phase,and the matrix,creating extensive lattice distortions at the interfaces.An increase in the Cu-rich phase content promoted the interaction between phases,enhancing the strain energy of the alloy and the barrier strength of the interfaces.The calcu-latedτint values,ranging from approximately 5.92-6.69 GPa,are significantly higher than those found in traditional alloys,providing a benchmark for designing new high-performance medium-entropy alloys.展开更多
Efficient electrocatalysts are vital to large-current hydrogen production in commercial water splitting for green energy generation.Herein,a novel heterophase engineering strategy is described to produce polymorphic C...Efficient electrocatalysts are vital to large-current hydrogen production in commercial water splitting for green energy generation.Herein,a novel heterophase engineering strategy is described to produce polymorphic CoSe_(2)electrocatalysts.The composition of the electrocatalysts consisting of both cubic CoSe_(2)(c-CoSe_(2))and orthorhombic CoSe_(2)(o-CoSe_(2))phases can be controlled precisely.Our results demonstrate that junction-induced spin-state modulation of Co atoms enhances the adsorption of intermediates and accelerates charge transfer resulting in superior large-current hydrogen evolution reaction(HER)properties.Specifically,the CoSe_(2)based heterophase catalyst with the optimal c-CoSe_(2)content requires an overpotential of merely 240 mV to achieve 1,000 mA·cm^(-2)as well as a Tafel slope of 50.4 mV·dec^(-1).Furthermore,the electrocatalyst can maintain a large current density of 1,500 mA·cm^(-2)for over 320 h without decay.The results reveal the advantages and potential of heterophase junction engineering pertaining to design and fabrication of low-cost transition metal catalysts for large-current water splitting.展开更多
Li-rich layered oxides have become one of the most concerned cathode materials for high-energy lithiumion batteries, but they still suffer from poor cycling stability and detrimental voltage decay, especially at eleva...Li-rich layered oxides have become one of the most concerned cathode materials for high-energy lithiumion batteries, but they still suffer from poor cycling stability and detrimental voltage decay, especially at elevated temperature. Herein, we proposed a surface heterophase coating engineering based on amorphous/crystalline Li3 PO4 to address these issues for Li-rich layered oxides via a facile wet chemical method. The heterophase coating layer combines the advantages of physical barrier effect achieved by amorphous Li3 PO4 with facilitated Li+diffusion stemmed from crystalline Li3 PO4. Consequently, the modified Li(1.2) Ni(0.2) Mn(0.6) O2 delivers higher initial coulombic efficiency of 92% with enhanced cycling stability at 55 °C(192.9 mAh/g after 100 cycles at 1 C). More importantly, the intrinsic voltage decay has been inhibited as well, i.e. the average potential drop per cycle decreases from 5.96 mV to 2.99 mV. This surface heterophase coating engineering provides an effective strategy to enhance the high-temperature electrochemical performances of Li-rich layered oxides and guides the direction of surface modification strategies for cathode materials in the future.展开更多
Heterojunction fabrication is one of the most effective strategies for enhancing the photocatalytic performance of semiconductor photocatalysts. Here, TiO2（B）/anatase nanowires with interfacial heterostructures were...Heterojunction fabrication is one of the most effective strategies for enhancing the photocatalytic performance of semiconductor photocatalysts. Here, TiO2（B）/anatase nanowires with interfacial heterostructures were prepared through a three-step synthesis method, including hydrothermal treatment, H＋ exchange, and annealing. The phase structures of the nanowires in the bulk and on the surface during the annealing process were monitored by XRD and UV-Raman spectroscopy, respectively. SEM and TEM results indicate that the TiO2（B） nanowires partially collapse and transform into anatase during the annealing process and the heterophase junction structure is formed simultaneously. On the basis of the phase structure together with morphology data, a phase-transformation mechanism was proposed. Photocatalytic activity was evaluated by hydrogen production and pollutant-degradation assays. The optimized structure of the photocatalyst contains 24% TiO2（B） in the bulk and 100% anatase on the surface. The charge-carrier behavior during the photocatalytic process was investigated by photocurrent, electrochemical impedance spectroscopy（EIS）, and photoluminescence（PL） spectroscopy, which revealed that the heterophase-junction structure in the bulk was responsible for the highly efficient charge separation and transportation, etc.; the anatase on the surface took control of the high surface-reaction activity.展开更多
The results of molecular dynamics calculations on the interfacial energies and atomic structures of Ag/Ni and Cu/Ni interfaces are presented. Calculation on Ag/Ni interfaces with low-index planes shows that those cont...The results of molecular dynamics calculations on the interfacial energies and atomic structures of Ag/Ni and Cu/Ni interfaces are presented. Calculation on Ag/Ni interfaces with low-index planes shows that those containing the (111) plane have the lowest energies, which is in agreement with the experiments. Comparing surface energy with interfacial energy, it is found the order of the interfacial energies of Ag/Ni and Cu/Ni containing the planes fall in the same order as solid-vapor surface energies of Ag, Cu and Ni. In this MD simulation, the relaxed atomic structure and dislocation network of (110)_Ag||(110)Ni interface are coincident to HREM observations.展开更多
The debromination of diphenyl bromomethane (Ph_2CHBr) using polymers with viologen structure as electron--transfer catalyst (ETC) afforded tetraphenylethane in good yields under het- erophase conditions.
Sn-based electrocatalysts have been gaining increasing attention due to their potential contribution in the conversion of CO2 into HCOOH driven by sustainable energy sources;however,their actual capability to catalyze...Sn-based electrocatalysts have been gaining increasing attention due to their potential contribution in the conversion of CO2 into HCOOH driven by sustainable energy sources;however,their actual capability to catalyze CO2 reduction reaction(CO2RR)still cannot meet the requirements of commercial-scale applications.Therefore developing Snbased catalyst is of vital importance.Herein,the sheet-like heterophase Sn O2/Sn3O4 with a high density of phase interfaces has been first engineered by a facile hydrothermal process,with Sn3O4 as the dominant phase.The evidences from experiments and theoretical simulation indicate that the charge redistribution and built-in electric field at heterophase interfaces boost CO2 adsorption and HCOO*formation,accelerate the charge transfer between the catalysts and reactants,and ultimately greatly elevate the intrinsic activity of the heterophase Sn O2/Sn3O4 towards CO2 RR.Meanwhile,the in-situ generated porous structure and metal Sn during CO2 RR improve the mass transmission within the interlayer volume and the conductivity of Sn O2/Sn3O4.The heterophase Sn O2/Sn3O4 displays high activity and selectivity for CO2 RR,achieving an improvement in CO2 reduction current density,88.3%Faradaic efficiency of HCOOH conversion at-0.9 VRHE,along with a long-term tolerance in CO2 RR.This study demonstrates that heterophase interface engineering is an efficient strategy to regulate advanced catalysts for different applications.展开更多
Heterophase nanomaterials composed of multiple phases have attracted increasing attention due to their enhanced performance in electrocatalytic field.Nevertheless,constructing two-dimensional(2D)crystalline/amorphous ...Heterophase nanomaterials composed of multiple phases have attracted increasing attention due to their enhanced performance in electrocatalytic field.Nevertheless,constructing two-dimensional(2D)crystalline/amorphous heterophase nanostructures with the samechemical composition remains a great challenge.Herein,we report the preparation of a 2D crystalline/amorphous heterophase of MoS2 nanosheets with the same elemental components via a facile solvothermal method.展开更多
Generating heterophase structures in nanomaterials,e.g.,heterophase metal nanocrystals,is an effective way to tune their physicochemical properties because of their high-energy nature and unique electronic environment...Generating heterophase structures in nanomaterials,e.g.,heterophase metal nanocrystals,is an effective way to tune their physicochemical properties because of their high-energy nature and unique electronic environment of the generated interfaces.However,the direct synthesis of heterophase metal nanocrystals remains a great challenge due to their unstable nature.Herein,we report the in situar direct synthesis of heterophase Ni nanocrystals on graphene.The heterostructure of face-centered cubic(fee)and hexagonal close-packed(hep)phase was generated via the epitaxial growth of hep Ni and the partial transformation of fee Ni and stabilized by the anchoring effect of graphene toward fee Ni nanocrystal and the preferential adsorption of surfactant polyethylenimine(PEI)toward epitaxial hep Ni.Comparing with the fee Ni nanocrystals grown on graphene,the heterophase(fcc/hcp)Ni nanocrystals in situ grown on graphene showed a greatly improved catalytic activity and reusability in 4-nitrophenol(4-NP)reduction to 4-aminophenol(4-AP).The measured apparent rate constant and the activity parameter were 2.958 min^(-1) and 102 min^(-1)·mg^(-1),respectively,higher than that of the best reported non-noble metal catalysts and most noble metal catalysts.The control experiments and density functional theory calculations reveal that the interface of the fee and hep phases enhances the adsorption of substrate 4-NP and thus facilitates the reaction kinetics.This work proves the novel idea for the rational design of heterophase metal nanocrystals by employing the synergistic effect of surfactant and support,and also the potential of creating the heterostructure for enhancing their catalytic reactivity.展开更多
To solve the problem of high photogenerated carrier recombination rate and low photoelectric conversion efficiency of TiO_(2)-based materials,a simple N-doped anatase/rutile TiO_(2) heterophase nanorod film was design...To solve the problem of high photogenerated carrier recombination rate and low photoelectric conversion efficiency of TiO_(2)-based materials,a simple N-doped anatase/rutile TiO_(2) heterophase nanorod film was designed by a low-temperature hydrothermal method in this work.The enhanced separation and transport of photogenerated charges were facilitated by the smaller contact barrier and appropriate band matching between anatase TiO_(2)nanoparticles and rutile TiO_(2) nanorods.The introduction of N doping in anatase TiO_(2) resulted in an upward shift of the valence band and a narrowing of the band gap,consequently enhancing the efficiency of visible light utilization.The combination of the heterophase junction and N-doping exhibited a synergistic effect,effectively suppressing the recombination of photogenerated charges and enhancing the photoelectric conversion efficiency of the photoanode.Under AM 1.5G irradiation,the photocurrent density(J)of the A-TO(N)@R-TONR photoanode reached2.19 mA·cm^(-2)(V_(RHE,1.23 eV)).Additionally,the incident photon-electron conversion efficiency(IPCE)and the charge injection efficiency(η)reached 81.4%and 51.6%at320 nm.Furthermore,the J,IPCE,andηvalues of the A-TO(N)@R-TONR photoanode were 2.96,2.1 and 3.2times those of pure R-TONR photoanode,respectively.This work presents a rational strategy for designing efficient TiO_(2)-based photoanodes.展开更多
The supercapacitor electrode materials suffer from structure pulverization and sluggish electrode kinetics under high current rates.Herein,a unique NiMoO_(4)@Co-B heterostructure composed of highly conductive Co-B nan...The supercapacitor electrode materials suffer from structure pulverization and sluggish electrode kinetics under high current rates.Herein,a unique NiMoO_(4)@Co-B heterostructure composed of highly conductive Co-B nanoflakes and a semiconductive NiMoO_(4) nanorod is designed as an electrode material to exert the energy storage effect on supercapacitors.The formed Mott-Schottky heterostructure is helpful to overcome the ion diffusion barrier and charge transfer resistance during charging and discharging.Moreover,this crystalline-amorphous heterogeneous phase could provide additional ion storage sites and better strain adaptability.Remarkably,the optimized NiMoO_(4)@Co-B hierarchical nanorods(the mass ratio of NiMoO_(4)/Co-B is 3:1)present greatly enhanced electrochemical characteristics compared with other components,and show superior specific capacity of 236.2 mA h g^(-1)at the current density of 0.5 A g^(-1),as well as remarked rate capability.The present work broadens the horizons of advanced electrode design with distinct heterogeneous interface in other energy storage and conversion field.展开更多
The construction of heterophase junctions by rutile-anatase TiO2is considered an effective strategy for toluene degradation, but the photogenerated electron utilization is still insufficient. In this study, the format...The construction of heterophase junctions by rutile-anatase TiO2is considered an effective strategy for toluene degradation, but the photogenerated electron utilization is still insufficient. In this study, the formation of type-II heterojunction by the encapsulation of Materials of Institut Lavoisier(MIL-101) by anatase is performed, and then the heterophase junction is further constructed to improve the catalytic performance of the photocatalyst.The enhancement of photocatalytic performance depends on the encapsulation of MIL-101by anatase, the light absorption capacity of anatase, and the contact area of two heterojunctions. Photogenerated electrons are transferred to oxygen vacancies of anatase and promoting the generation of oxygen-containing radicals. The material certifies the synergistic effect of the heterophase junction and heterojunction design and provides a theoretical basis for application in the degradation of volatile organic compounds.展开更多
Two-dimensional(2 D) platinum(Pt)-based nanomaterials are considered as the ideal fuel cell catalysts, while their rational synthesis associated with phase control remains a formidable challenge. Herein, we firstly de...Two-dimensional(2 D) platinum(Pt)-based nanomaterials are considered as the ideal fuel cell catalysts, while their rational synthesis associated with phase control remains a formidable challenge. Herein, we firstly design the novel 2 D Pt-lead-sulphur heterophased nanosheets(Pt Pb S HPNSs) as efficient high-toleration electrocatalysts for methanol oxidation reaction(MOR).They exhibit much higher activity and more highlighted bifunctional antipoisoning abilities than Pt Pb NSs and commercial Pt/C.Further density functional theory(DFT) simulation verifies that the decreased electron density of Pt sites worked by Pb and S makes CO intermediate favorable to desorb, avoiding the formation of CO*-polluted Pt sites. Simultaneously, this heterophased interface effectively weakens the adsorption of S^(2-)-species and improves the S-poisoning tolerance, showing a route to realize nearly innoxious catalysis. The present work highlights the importance of heterophase control in tuning antipoisoning property for 2 D Pt-based nanomaterials, which is key for the rational design of efficient fuel cell anodic catalysts.展开更多
In the past decades,metal-containing nanomaterials have attracted increasing interests owing to their intriguing physicochemical properties and various promising applications.Recent research has revealed that the phas...In the past decades,metal-containing nanomaterials have attracted increasing interests owing to their intriguing physicochemical properties and various promising applications.Recent research has revealed that the phase of metal-containing nanomaterials could significantly affect their properties and functions.In particular,nanomaterials with amorphous phase,which possess long-range disordered atomic arrangements,and the amorphous/crystalline heterophase nanostructures comprised of both amorphous and crystalline phases,have exhibited superior performance in various applications,e.g.,catalysis and energy storage.In this review,a brief overview of the recent progress on the wet-chemical synthesis and applications of amorphous and amorphous/crystalline heterophase metal-containing nanomaterials has been provided.Subsequently,on the basis of different categories of metal-containing nanomaterials,including metals,metal alloys,and metal compounds,their synthetic routes and promising applications will be highlighted.Finally,current challenges and some personal perspectives in this emerging research field will be proposed.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.U2341254)the National Natural Science Foundation of China(Grant No.52071124),the Natural Science Foundation of Jiangsu Province(No.BK20230502)the Jiangsu Funding Program for Excellent Postdoctoral Talent(No.2022ZB547).
文摘The unique structure and formation mechanism of medium-entropy alloys(MEAs)generally result in bet-ter comprehensive properties than traditional alloys.However,the strength-ductility trade-offremains a bottleneck,which limits their applications.In this study,we designed novel high-performance CrNiCu x MEAs with a heterophase composition by incorporating a Cu-rich phase,and they were fabricated using laser-directed energy deposition(LDED).The results show that synergistic strengthening from multiple phases significantly improved the mechanical properties of the alloys,resulting in a tensile strength of 675 MPa and a ductility of 34.4%,demonstrating an excellent combination of high tensile strength and ductility.The improved mechanical properties of the CrNiCu x medium-entropy alloys are primarily due to the heterophase interfacial strengthening mechanism.In the alloy,numerous semi-coherent and coher-ent interfaces formed between the Cr-rich phase,Cu-rich phase,and the matrix,creating extensive lattice distortions at the interfaces.An increase in the Cu-rich phase content promoted the interaction between phases,enhancing the strain energy of the alloy and the barrier strength of the interfaces.The calcu-latedτint values,ranging from approximately 5.92-6.69 GPa,are significantly higher than those found in traditional alloys,providing a benchmark for designing new high-performance medium-entropy alloys.
基金financially supported by the National Natural Science Foundation of China(Nos.52002294 and 52202111)the Key Research and Development Program of Hubei Province(No.2021BAA208)+3 种基金the Knowledge Innovation Program of Wuhan-Shuguang Project(No.2022010801020364)City University of Hong Kong Donation Research Grant(No.DON-RMG 9229021)City University of Hong Kong Donation Grant(No.9220061)City University of Hong Kong Strategic Research Grant(SRG)(No.7005505)。
文摘Efficient electrocatalysts are vital to large-current hydrogen production in commercial water splitting for green energy generation.Herein,a novel heterophase engineering strategy is described to produce polymorphic CoSe_(2)electrocatalysts.The composition of the electrocatalysts consisting of both cubic CoSe_(2)(c-CoSe_(2))and orthorhombic CoSe_(2)(o-CoSe_(2))phases can be controlled precisely.Our results demonstrate that junction-induced spin-state modulation of Co atoms enhances the adsorption of intermediates and accelerates charge transfer resulting in superior large-current hydrogen evolution reaction(HER)properties.Specifically,the CoSe_(2)based heterophase catalyst with the optimal c-CoSe_(2)content requires an overpotential of merely 240 mV to achieve 1,000 mA·cm^(-2)as well as a Tafel slope of 50.4 mV·dec^(-1).Furthermore,the electrocatalyst can maintain a large current density of 1,500 mA·cm^(-2)for over 320 h without decay.The results reveal the advantages and potential of heterophase junction engineering pertaining to design and fabrication of low-cost transition metal catalysts for large-current water splitting.
基金supported by the National Key R&D Program of China (2016YFB0100301)the National Natural Science Foundation of China (51802020, 51802019)+1 种基金the Beijing Institute of Technology Research Fund Program for Young Scholarsthe Young Elite Scientists Sponsorship Program by CAST (2018QNRC001。
文摘Li-rich layered oxides have become one of the most concerned cathode materials for high-energy lithiumion batteries, but they still suffer from poor cycling stability and detrimental voltage decay, especially at elevated temperature. Herein, we proposed a surface heterophase coating engineering based on amorphous/crystalline Li3 PO4 to address these issues for Li-rich layered oxides via a facile wet chemical method. The heterophase coating layer combines the advantages of physical barrier effect achieved by amorphous Li3 PO4 with facilitated Li+diffusion stemmed from crystalline Li3 PO4. Consequently, the modified Li(1.2) Ni(0.2) Mn(0.6) O2 delivers higher initial coulombic efficiency of 92% with enhanced cycling stability at 55 °C(192.9 mAh/g after 100 cycles at 1 C). More importantly, the intrinsic voltage decay has been inhibited as well, i.e. the average potential drop per cycle decreases from 5.96 mV to 2.99 mV. This surface heterophase coating engineering provides an effective strategy to enhance the high-temperature electrochemical performances of Li-rich layered oxides and guides the direction of surface modification strategies for cathode materials in the future.
基金supported by the National Natural Science Foundation of China(21603134)Young Talent Fund of University Association for Science and Technology in Shaanxi,China(20150104)+1 种基金Natural Science Basic Research Plan in Shaanxi Province of China(2016JQ2023)the Fundamental Research Funds for the Central Universities(GK201603032)~~
文摘Heterojunction fabrication is one of the most effective strategies for enhancing the photocatalytic performance of semiconductor photocatalysts. Here, TiO2（B）/anatase nanowires with interfacial heterostructures were prepared through a three-step synthesis method, including hydrothermal treatment, H＋ exchange, and annealing. The phase structures of the nanowires in the bulk and on the surface during the annealing process were monitored by XRD and UV-Raman spectroscopy, respectively. SEM and TEM results indicate that the TiO2（B） nanowires partially collapse and transform into anatase during the annealing process and the heterophase junction structure is formed simultaneously. On the basis of the phase structure together with morphology data, a phase-transformation mechanism was proposed. Photocatalytic activity was evaluated by hydrogen production and pollutant-degradation assays. The optimized structure of the photocatalyst contains 24% TiO2（B） in the bulk and 100% anatase on the surface. The charge-carrier behavior during the photocatalytic process was investigated by photocurrent, electrochemical impedance spectroscopy（EIS）, and photoluminescence（PL） spectroscopy, which revealed that the heterophase-junction structure in the bulk was responsible for the highly efficient charge separation and transportation, etc.; the anatase on the surface took control of the high surface-reaction activity.
基金The authors would like to acknowledge the financial support by the Special Funds for the Major State Basic Research Projects of China(Grant No.G20000670104).
文摘The results of molecular dynamics calculations on the interfacial energies and atomic structures of Ag/Ni and Cu/Ni interfaces are presented. Calculation on Ag/Ni interfaces with low-index planes shows that those containing the (111) plane have the lowest energies, which is in agreement with the experiments. Comparing surface energy with interfacial energy, it is found the order of the interfacial energies of Ag/Ni and Cu/Ni containing the planes fall in the same order as solid-vapor surface energies of Ag, Cu and Ni. In this MD simulation, the relaxed atomic structure and dislocation network of (110)_Ag||(110)Ni interface are coincident to HREM observations.
文摘The debromination of diphenyl bromomethane (Ph_2CHBr) using polymers with viologen structure as electron--transfer catalyst (ETC) afforded tetraphenylethane in good yields under het- erophase conditions.
基金the National Natural Science Foundation of China(21573062,21631004 and 21901065)the Natural Science Foundation of Heilongjiang Province(B2018008)+1 种基金the Youth Science and Technology Innovation Team Project of Heilongjiang Province(2018-KYYWF-1593)the University Nursing Program for Young Scholars with Creative Talents in Heilongjiang Province(UNPYSCT-2018009)。
文摘Sn-based electrocatalysts have been gaining increasing attention due to their potential contribution in the conversion of CO2 into HCOOH driven by sustainable energy sources;however,their actual capability to catalyze CO2 reduction reaction(CO2RR)still cannot meet the requirements of commercial-scale applications.Therefore developing Snbased catalyst is of vital importance.Herein,the sheet-like heterophase Sn O2/Sn3O4 with a high density of phase interfaces has been first engineered by a facile hydrothermal process,with Sn3O4 as the dominant phase.The evidences from experiments and theoretical simulation indicate that the charge redistribution and built-in electric field at heterophase interfaces boost CO2 adsorption and HCOO*formation,accelerate the charge transfer between the catalysts and reactants,and ultimately greatly elevate the intrinsic activity of the heterophase Sn O2/Sn3O4 towards CO2 RR.Meanwhile,the in-situ generated porous structure and metal Sn during CO2 RR improve the mass transmission within the interlayer volume and the conductivity of Sn O2/Sn3O4.The heterophase Sn O2/Sn3O4 displays high activity and selectivity for CO2 RR,achieving an improvement in CO2 reduction current density,88.3%Faradaic efficiency of HCOOH conversion at-0.9 VRHE,along with a long-term tolerance in CO2 RR.This study demonstrates that heterophase interface engineering is an efficient strategy to regulate advanced catalysts for different applications.
基金supported by the National Natural Science Foundation of China(no.21971117)Functional Research Funds for the Central Universities,Nankai University(no.63186005)+6 种基金Tianjin Key Lab for Rare Earth Materials and Applications(no.ZB19500202)the Open Funds(no.RERU2019001)of the State Key Laboratory of Rare Earth Resource Utilization,111 Project(no.B18030)from China,Beijing–Tianjin–Hebei Collaborative Innovation Project(no.19YFSLQY00030)the Outstanding Youth Project of TianjinNatural Science Foundation(no.20JCJQJC00130)the Key Project of Tianjin Natural Science Foundation(no.20JCZDJC00650)fundings from Basic Scientific Research in Central Universities(grant no.G2020KY0535)the Foundation of Shaanxi Province Natural Science Basic Research Program(grant nos.2021JQ-095 and 2020JQ-146)Postdoctoral Science Foundation of China(nos.2019TQ0265 and 2019M663809).
文摘Heterophase nanomaterials composed of multiple phases have attracted increasing attention due to their enhanced performance in electrocatalytic field.Nevertheless,constructing two-dimensional(2D)crystalline/amorphous heterophase nanostructures with the samechemical composition remains a great challenge.Herein,we report the preparation of a 2D crystalline/amorphous heterophase of MoS2 nanosheets with the same elemental components via a facile solvothermal method.
基金funded by the National Natural Science Foundation of China(No.21776286).
文摘Generating heterophase structures in nanomaterials,e.g.,heterophase metal nanocrystals,is an effective way to tune their physicochemical properties because of their high-energy nature and unique electronic environment of the generated interfaces.However,the direct synthesis of heterophase metal nanocrystals remains a great challenge due to their unstable nature.Herein,we report the in situar direct synthesis of heterophase Ni nanocrystals on graphene.The heterostructure of face-centered cubic(fee)and hexagonal close-packed(hep)phase was generated via the epitaxial growth of hep Ni and the partial transformation of fee Ni and stabilized by the anchoring effect of graphene toward fee Ni nanocrystal and the preferential adsorption of surfactant polyethylenimine(PEI)toward epitaxial hep Ni.Comparing with the fee Ni nanocrystals grown on graphene,the heterophase(fcc/hcp)Ni nanocrystals in situ grown on graphene showed a greatly improved catalytic activity and reusability in 4-nitrophenol(4-NP)reduction to 4-aminophenol(4-AP).The measured apparent rate constant and the activity parameter were 2.958 min^(-1) and 102 min^(-1)·mg^(-1),respectively,higher than that of the best reported non-noble metal catalysts and most noble metal catalysts.The control experiments and density functional theory calculations reveal that the interface of the fee and hep phases enhances the adsorption of substrate 4-NP and thus facilitates the reaction kinetics.This work proves the novel idea for the rational design of heterophase metal nanocrystals by employing the synergistic effect of surfactant and support,and also the potential of creating the heterostructure for enhancing their catalytic reactivity.
基金financially supported by the University Natural Science Research Project of Anhui Province(No.2022AH050848)the Graduate Innovation Fund of Anhui Province(No.2022xscx082)the National Natural Science Foundation of China(No.12304134)。
文摘To solve the problem of high photogenerated carrier recombination rate and low photoelectric conversion efficiency of TiO_(2)-based materials,a simple N-doped anatase/rutile TiO_(2) heterophase nanorod film was designed by a low-temperature hydrothermal method in this work.The enhanced separation and transport of photogenerated charges were facilitated by the smaller contact barrier and appropriate band matching between anatase TiO_(2)nanoparticles and rutile TiO_(2) nanorods.The introduction of N doping in anatase TiO_(2) resulted in an upward shift of the valence band and a narrowing of the band gap,consequently enhancing the efficiency of visible light utilization.The combination of the heterophase junction and N-doping exhibited a synergistic effect,effectively suppressing the recombination of photogenerated charges and enhancing the photoelectric conversion efficiency of the photoanode.Under AM 1.5G irradiation,the photocurrent density(J)of the A-TO(N)@R-TONR photoanode reached2.19 mA·cm^(-2)(V_(RHE,1.23 eV)).Additionally,the incident photon-electron conversion efficiency(IPCE)and the charge injection efficiency(η)reached 81.4%and 51.6%at320 nm.Furthermore,the J,IPCE,andηvalues of the A-TO(N)@R-TONR photoanode were 2.96,2.1 and 3.2times those of pure R-TONR photoanode,respectively.This work presents a rational strategy for designing efficient TiO_(2)-based photoanodes.
基金supported by the National Natural Science Foundation of China(52261040,51971104)the Outstanding Postgraduate Innovation Star Project of Gansu Provincial Department of Education(2022CXZX-383)。
文摘The supercapacitor electrode materials suffer from structure pulverization and sluggish electrode kinetics under high current rates.Herein,a unique NiMoO_(4)@Co-B heterostructure composed of highly conductive Co-B nanoflakes and a semiconductive NiMoO_(4) nanorod is designed as an electrode material to exert the energy storage effect on supercapacitors.The formed Mott-Schottky heterostructure is helpful to overcome the ion diffusion barrier and charge transfer resistance during charging and discharging.Moreover,this crystalline-amorphous heterogeneous phase could provide additional ion storage sites and better strain adaptability.Remarkably,the optimized NiMoO_(4)@Co-B hierarchical nanorods(the mass ratio of NiMoO_(4)/Co-B is 3:1)present greatly enhanced electrochemical characteristics compared with other components,and show superior specific capacity of 236.2 mA h g^(-1)at the current density of 0.5 A g^(-1),as well as remarked rate capability.The present work broadens the horizons of advanced electrode design with distinct heterogeneous interface in other energy storage and conversion field.
基金sponsored financially by the National Natural Science Foundation of China (No. 12175145)the Shanghai Rising-Star Program (No. 21QA1406600)。
文摘The construction of heterophase junctions by rutile-anatase TiO2is considered an effective strategy for toluene degradation, but the photogenerated electron utilization is still insufficient. In this study, the formation of type-II heterojunction by the encapsulation of Materials of Institut Lavoisier(MIL-101) by anatase is performed, and then the heterophase junction is further constructed to improve the catalytic performance of the photocatalyst.The enhancement of photocatalytic performance depends on the encapsulation of MIL-101by anatase, the light absorption capacity of anatase, and the contact area of two heterojunctions. Photogenerated electrons are transferred to oxygen vacancies of anatase and promoting the generation of oxygen-containing radicals. The material certifies the synergistic effect of the heterophase junction and heterojunction design and provides a theoretical basis for application in the degradation of volatile organic compounds.
基金supported by the National Natural Science Foundation of China(92061201,21825106,22102155,and 32072304)China Postdoctoral Science Foundation(2021M692909 and 2022T150587)+1 种基金the Program for Innovative Research Team(in Science and Technology)in Universities of Henan Province and Zhengzhou University(19IRSTHN022)the Key Scientific and Technological Project of Henan Province(2021102210027)。
基金supported by the Ministry of Science and Technology of China (2017YFA0208200, 2016YFA0204100)the National Natural Science Foundation of China (22025108)the Start-Up support from Xiamen University。
文摘Two-dimensional(2 D) platinum(Pt)-based nanomaterials are considered as the ideal fuel cell catalysts, while their rational synthesis associated with phase control remains a formidable challenge. Herein, we firstly design the novel 2 D Pt-lead-sulphur heterophased nanosheets(Pt Pb S HPNSs) as efficient high-toleration electrocatalysts for methanol oxidation reaction(MOR).They exhibit much higher activity and more highlighted bifunctional antipoisoning abilities than Pt Pb NSs and commercial Pt/C.Further density functional theory(DFT) simulation verifies that the decreased electron density of Pt sites worked by Pb and S makes CO intermediate favorable to desorb, avoiding the formation of CO*-polluted Pt sites. Simultaneously, this heterophased interface effectively weakens the adsorption of S^(2-)-species and improves the S-poisoning tolerance, showing a route to realize nearly innoxious catalysis. The present work highlights the importance of heterophase control in tuning antipoisoning property for 2 D Pt-based nanomaterials, which is key for the rational design of efficient fuel cell anodic catalysts.
基金supported by the grants(Nos.9610478,9680314,7020013,and 1886921)the Start-Up Grant(No.9380100),ITC via the Hong Kong Branch of the National Precious Metals Material Engineering Research Center(NPMM)from City University of Hong Kong,the Research Grants Council of Hong Kong,China(No.AoE/P-701/20)the Science Technology and Innovation Committee of Shenzhen Municipality(Nos.JCYJ20200109143412311 and SGDX2020110309300301,“Preparation of single atoms on transition metal chalcogenides for electrolytic hydrogen evolution”,CityU).
文摘In the past decades,metal-containing nanomaterials have attracted increasing interests owing to their intriguing physicochemical properties and various promising applications.Recent research has revealed that the phase of metal-containing nanomaterials could significantly affect their properties and functions.In particular,nanomaterials with amorphous phase,which possess long-range disordered atomic arrangements,and the amorphous/crystalline heterophase nanostructures comprised of both amorphous and crystalline phases,have exhibited superior performance in various applications,e.g.,catalysis and energy storage.In this review,a brief overview of the recent progress on the wet-chemical synthesis and applications of amorphous and amorphous/crystalline heterophase metal-containing nanomaterials has been provided.Subsequently,on the basis of different categories of metal-containing nanomaterials,including metals,metal alloys,and metal compounds,their synthetic routes and promising applications will be highlighted.Finally,current challenges and some personal perspectives in this emerging research field will be proposed.
