With tunable local electronic environment,high mass density of MN4sites,and ease of preparation,metal-organic conjugated coordinative polymer(CCP) with inherent electronic conductivity provides a promising alternative...With tunable local electronic environment,high mass density of MN4sites,and ease of preparation,metal-organic conjugated coordinative polymer(CCP) with inherent electronic conductivity provides a promising alternative to the well-known M-N-C electrocatalysts.Herein,the coordination reaction between Cu^(2+)and 1,2,4,5-tetraaminobenzene(TAB) was conducted on the surface of metallic Cu nanowires,forming a thin layer of CuN4-based CCP(Cu-TAB) on the Cu nanowire.More importantly,interfacial transfer of electrons from Cu core to the CuN4-based CCP nanoshell was observed within the resulting CuTAB@Cu,which was found to enrich the local electronic density of the CuN4sites.As such,the CuTAB@Cu demonstrates much improved affinity to the*COOH intermediate formed from the rate determining step;the energy barrier for C-C coupling,which is critical to convert CO_(2)into C2products,is also decreased.Accordingly,it delivers a current density of-9.1 mA cm^(-2)at a potential as high as 0.558 V(vs.RHE) in H-type cell and a Faraday efficiency of 46.4% for ethanol.This work emphasizes the profound role of interfacial interaction in tuning the local electronic structure and activating the CuN4-based CCPs for efficient electroreduction of CO_(2).展开更多
The modulation of electrical properties of MoS_2 has attracted extensive research interest because of its potential applications in electronic and optoelectronic devices.Herein,interfacial charge transfer induced elec...The modulation of electrical properties of MoS_2 has attracted extensive research interest because of its potential applications in electronic and optoelectronic devices.Herein,interfacial charge transfer induced electronic property tuning of MoS_2 are investigated by in situ ultraviolet photoelectron spectroscopy and x-ray photoelectron spectroscopy measurements.A downward band-bending of MoS_2-related electronic states along with the decreasing work function,which are induced by the electron transfer from Cs overlayers to MoS_2,is observed after the functionalization of MoS_2 with Cs,leading to n-type doping.Meanwhile,when MoS_2 is modified with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane(F_4-TCNQ),an upward band-bending of MoS_2-related electronic states along with the increasing work function is observed at the interfaces.This is attributed to the electron depletion within MoS_2 due to the strong electron withdrawing property of F_4-TCNQ,indicating p-type doping of MoS_2.Our findings reveal that surface transfer doping is an effective approach for electronic property tuning of MoS_2 and paves the way to optimize its performance in electronic and optoelectronic devices.展开更多
Anodic oxygen evolution reaction(OER)is the key bottleneck for water electrolysis technique owing to its sluggish reaction kinetics.Interfacial engineering on the rationally designed heterostructure can regulate the e...Anodic oxygen evolution reaction(OER)is the key bottleneck for water electrolysis technique owing to its sluggish reaction kinetics.Interfacial engineering on the rationally designed heterostructure can regulate the electronic states efficiently for intrinsic activity improvement.Here,we report a co-phosphorization approach to construct a VPO_(4)-Ni_(2)P heterostructure on nickel foam with strongly chemical binding,wherein phosphate acts as electronic modifier for Ni_(2)P electrocatalyst.Profiting from the interfacial interaction,it is uncovered that electron shifts from Ni_(2)P to VPO_(4)to render valence increment in Ni species.Such an electronic manipulation rationalizes the chemical affinities of various oxygen intermediates in OER pathway,giving a substantially reduced energy barrier.As a result,the advanced VPO_(4)-Ni_(2)P heterostructure only requires an overpotential of 289 mV to deliver a high current density of 350 mA/cm^(2)for OER in alkaline electrolyte,together with a Tafel slope as low as 28 mV/dec.This work brings fresh insights into interfacial engineering for advanced electrocatalyst design.展开更多
Electron donors(EDs)are widely used to improve the H 2 production performance of Schottky junction photocatalysts,but the functions of EDs are still unknown from the perspective of electron transfer dy-namics.Herein,P...Electron donors(EDs)are widely used to improve the H 2 production performance of Schottky junction photocatalysts,but the functions of EDs are still unknown from the perspective of electron transfer dy-namics.Herein,Pt nanocluster-decorated CdS nanorod is successfully prepared to construct a typical CdS/Pt Schottky junction.Pt nanoclusters with a diameter of∼2 nm are deposited on the surface of CdS nanorods by in situ photoreduction at sub-zero temperature.The CdS/Pt photocatalyst using lactic acid shows a higher H_(2)production rate of 4762μmol g^(-1)h^(-1)compared to that using methanol,tri-ethanolamine,and glycerol.To understand the cause,the dynamics of photogenerated carriers in CdS/Pt photocatalysts during ED-assisted H_(2)production are revealed by femtosecond transient absorption spec-troscopy.Among the four organic EDs,lactic acid enables the fastest electron transfer rate of 1.8×10^(9)s^(-1)and the highest electron transfer efficiency of 76%at the CdS/Pt interface due to the most efficient hole consumption.This work sheds light on the importance of efficient interfacial electron transfer for im-proving the photocatalytic performance of Schottky junction photocatalysts.展开更多
Constructing step-scheme(S-scheme)heterojunctions can considerably facilitate separation and transfer of photocarriers,as well as promote strong redox ability.The interface resistance of heterojunctions immediately af...Constructing step-scheme(S-scheme)heterojunctions can considerably facilitate separation and transfer of photocarriers,as well as promote strong redox ability.The interface resistance of heterojunctions immediately affects photocarrier separation and determines the photocatalytic activity.Herein,we constructed a novel Bi OBr/Ni_(2)P/g-C_(3)N_(4) heterojunction using Ni_(2)P as a novel electron bridge to reduce the interfacial resistance of photocarriers between Bi OBr and g-C3N4.The as-prepared 10% BiOBr/Ni2P/g-C_(3)N_(4) sample exhibited outstanding visible-light photocatalytic performance for methyl orange and rhodamine B removal,with degradation efficiencies of 91.4% and 98.9%,respectively.The excellent photocatalytic activity of Bi OBr/Ni_(2)P/g-C_(3)N_(4) was mainly attributed to the synergistic effects of the Ni2P cocatalyst and S-scheme heterojunction,which not only reduced the interface resistance but also retained the strong redox potential of the photocarriers.In addition,the formation of the S-scheme system was supported by active oxygen species investigation,current-voltage curves,and density functional theory calculations.This work provides a guideline for the design of highly efficient S-scheme photocatalysts with transition metal phosphates as electron bridges to improve photocarriers separation.展开更多
The slow water dissociation is the rate-determining step that slows down the reaction rate in alkaline hydrogen evolution reaction(HER).Optimizing the surface electronic structure of the catalyst to lower the energy b...The slow water dissociation is the rate-determining step that slows down the reaction rate in alkaline hydrogen evolution reaction(HER).Optimizing the surface electronic structure of the catalyst to lower the energy barrier of water dissociation and regulating the binding strength of adsorption intermediates are crucial strategy for boosting the catalytic performance of HER.In this study,RuO_(2)/BaRuO_(3)(RBRO)heterostructures with abundant oxygen vacancies and lattice distortion were in-situ constructed under a low temperature via the thermal decomposition of gel-precursor.The RBRO heterostructures obtained at 550℃ exhibited the highest HER activity in 1 M KOH,showing an ultra-low overpotential of 16 mV at 10 mA cm^(-2)and a Tafel slope of 33.37 m V dec^(-1).Additionally,the material demonstrated remarkable durability,with only 25 mV of degradation in overpotential after 200 h of stability testing at 10 mA cm^(-2).Density functional theory calculations revealed that the redistribution of charges at the heterojunction interface can optimize the binding energies of H*and OH*and effectively lower the energy barrier of water dissociation.This research offers novel perspectives on surpassing the water dissociation threshold of alkaline HER catalysts by means of a systematic design of heterogeneous interfaces.展开更多
Molecular catalysts with well-defined single atom sites and coordination environments exhibit significant potential as oxygen reduction electrocatalysts,but suffering from the activity and stability issues.Herein,the ...Molecular catalysts with well-defined single atom sites and coordination environments exhibit significant potential as oxygen reduction electrocatalysts,but suffering from the activity and stability issues.Herein,the ultrathin carbon shell supported FePc molecule electrocatalysts(FePc/TA-ONG-N),featuring with a direct oxygen bridging between FePc and carbon substrate,were designed and synthesized.The direct connection with oxygen atom on carbon substrate,certified by the Fourier transform infrared spectroscopy(FTIR)and extended X-ray absorption fine structure(EXAFS),can remarkably enhance the interaction and facilitate electron transfer from Fe,leading to an improved activity by reducing adsorption strength of intermediate species through lowering the d-band center position.The resultant half-wave potential of 0.902 V together with a Tafel slope of 23.64 mV·dec^(−1)is superior to Pt/C and control samples.Such catalyst holds a promise as air-cathode electrocatalyst in Zn-air battery with excellent operation stability exceeding 80 h.The density functional theory(DFT)calculations and molecular dynamic simulations unveiled that the O-bridge can effectively stabilize the FePc molecule and function as electron buffer to donate/gain electrons to/from Fe atom during the adsorption of oxygenates.The current findings are insightful for developing molecular catalysts with high performance through substrate engineering and axial coordination.展开更多
The interracial electron transfer （IET） dynamics of single CdSe core/multilayer shell （CdS2MLZnCdS1MLZnSIML） quantum dots （QDs） on the （110） surface of a futile TiO2 single crystal and TiO2 nanoparticles have ...The interracial electron transfer （IET） dynamics of single CdSe core/multilayer shell （CdS2MLZnCdS1MLZnSIML） quantum dots （QDs） on the （110） surface of a futile TiO2 single crystal and TiO2 nanoparticles have been compared. The fluorescence decay rates of single QDs on TiO2 are faster than those on glass, an insulating substrate, due to lET from the QDs to TiO2. Whereas the average IET rates are similar for QDs on the single crystal and nanoparticles, the distribution of lET rates is much broader in the latter, indicating a broad distribution of QD adsorption sites on the TiO2 nanoparticles.展开更多
Pure ZnO exhibits low photocatalytic H_(2)O_(2)production activity due to the rapid charge recombination.To realize the spatial separation of photogenerated electrons and holes,constructing an electron transfer channe...Pure ZnO exhibits low photocatalytic H_(2)O_(2)production activity due to the rapid charge recombination.To realize the spatial separation of photogenerated electrons and holes,constructing an electron transfer channel on the ZnO surface is an effective approach.This study successfully modified the surface of ZnO using F^(-)(ZnO/F)by introducing NH4F in an aqueous phase photocatalytic system.The F^(-)is adsorbed on the ZnO surface by Coulombic force and significantly improves the photocatalytic H_(2)O_(2)production performance of ZnO,with the highest efficiency of 4137.2μmol,g·^(-1)·L^(-1)·h^(-1).The photocatalytic performance enhancement mechanism of ZnO/F is explained in terms of electron transfer dynamics by femtosecond transient absorption spectroscopy(fs-TAS)measurements.F^(-)surface modification constructs a new ultrafast electron transport pathway from the ZnO CB to F^(-),and the optimal ZnO/F exhibits the fastest interfacial electron transfer lifetime of 5.8 ps.The F^(-)surface modification effectively facilitates the charge separation,thereby increasing the number of electrons available for photocatalytic H_(2)O_(2)reaction.This study has revealed the roles of F^(-)surface modification in the photocatalytic H_(2)O_(2)production by ZnO and provides guidance for ionic modification to improve photocatalytic performance.展开更多
Electrochemical biomass oxidation has garnered considerable attention due to its low energy consumption and the production of high-value chemicals.Supported metal nanoparticle catalysts have been widely explored in el...Electrochemical biomass oxidation has garnered considerable attention due to its low energy consumption and the production of high-value chemicals.Supported metal nanoparticle catalysts have been widely explored in electrochemical 2,5-hydroxymethylfurfural oxidation reaction(HMFOR)but limited by their inhomogeneity to build a clear structure-ability relationship at atomic level.Atomically precise metal nanoclusters with well-defined composition,high purity and unique physichemical property are one kind of ideal model electrocatalyst.In this work,we regulate the microenvironment of catalytic sites in Ni Se_(2)utilizing atomically precise and charge tunnable Au_(25)nanoclusters.The electrochemical results reveal that after the modification of Au_(25)nanoclusters,the HMFOR ability of NiSe_(2)could be enhanced.Among them,the NiSe_(2)modified with Au_(25)^(-)clusters displayed the best electrocatalytic ability,in which the electrons were preferred to transfer from Au_(25)^(-)to NiSe_(2)substrate resulting in the electrons accumulation at the electrocatalyst surface.The enhanced electrochemical performance of electrocatalyst can be attributed to two key factors:(1)enhanced adsorption ability towards HMF due to the strong interaction between electron enriched surface and electrophilic furan rings;(2)fast electron transfer at Au_(25)^(-)/NiSe_(2)interface,resulting in the rapid structure evolution to form active Ni OOH sites.This study serves as a valuable reference for designing highly efficient,atomically precise metal nanocluster electrocatalysts for biomass upgrading.展开更多
Pore structure plays critical roles in electrode kinetics but very challenging to tailor porous nanowires with rationally distributed pore sizes in a bioelectrochemical system.Herein a hierarchically porous nanowires-...Pore structure plays critical roles in electrode kinetics but very challenging to tailor porous nanowires with rationally distributed pore sizes in a bioelectrochemical system.Herein a hierarchically porous nanowires-material is delicately tuned for an optimal pore structure by adjusting the weight percentage of SiO_(2)-hard template in an electrospinning precursor solution.The asprepared optimal electrospinning nanowires further used as an anode of microbial fuel cells(MFCs),delivering a maximum output power density of 1,407.42 mW·m^(−2)with 4.24 and 10 times higher than that of the non-porous fiber and carbon cloth anode,respectively.The great enhancement is attributed to the rational pore structure which offers the largest surface area while the rich-mesopores well match with the size of electron mediators for a high density of catalytic centers.This work provides thoughtful insights to design of hierarchical porous electrode for high-performance MFCs and other bioelectrochemical system devices.展开更多
Photocatalytic mineralization of recalcitrant contaminants like phenol in wastewater requires abundant hydroxyl radicals(·OH) to initiate the reaction prior to the ring-opening. We here increase the free energy f...Photocatalytic mineralization of recalcitrant contaminants like phenol in wastewater requires abundant hydroxyl radicals(·OH) to initiate the reaction prior to the ring-opening. We here increase the free energy for adsorption of O~* species on TiOsurface and slightly downshift the band position by tin doping. This can simultaneously promote the generation and suppress the annihilation of ·OH. Besides, tin doping can also facilitate semiconductor-cocatalyst-solution(SCS) interfacial electron transfer by lowering the potential barrier and synergistically enhance the photon utilization. By filming the photocatalyst onto our developed fixed bed reactors, the loss of photons resulting from undesirable absorption by contaminants can be alleviated. By these virtues, trace amount of phenol in wastewater can be efficiently mineralized.展开更多
基金The National Key Research and Development Program of China(2021YFA1502000 and 2022YFA1505300)the National Natural Science Foundation of China (22288102, 22072124)+1 种基金support from Beijing Synchrotron Radiation Facility (1W1B, BSRF)China Scholarship Council for the financial support。
文摘With tunable local electronic environment,high mass density of MN4sites,and ease of preparation,metal-organic conjugated coordinative polymer(CCP) with inherent electronic conductivity provides a promising alternative to the well-known M-N-C electrocatalysts.Herein,the coordination reaction between Cu^(2+)and 1,2,4,5-tetraaminobenzene(TAB) was conducted on the surface of metallic Cu nanowires,forming a thin layer of CuN4-based CCP(Cu-TAB) on the Cu nanowire.More importantly,interfacial transfer of electrons from Cu core to the CuN4-based CCP nanoshell was observed within the resulting CuTAB@Cu,which was found to enrich the local electronic density of the CuN4sites.As such,the CuTAB@Cu demonstrates much improved affinity to the*COOH intermediate formed from the rate determining step;the energy barrier for C-C coupling,which is critical to convert CO_(2)into C2products,is also decreased.Accordingly,it delivers a current density of-9.1 mA cm^(-2)at a potential as high as 0.558 V(vs.RHE) in H-type cell and a Faraday efficiency of 46.4% for ethanol.This work emphasizes the profound role of interfacial interaction in tuning the local electronic structure and activating the CuN4-based CCPs for efficient electroreduction of CO_(2).
基金Supported by the National Natural Science Foundation of China (Grant No.22002031)the Natural Science Foundation of Zhejiang Province (Grant No.LY18F010019)the Innovation Project in Hangzhou for Returned Scholar。
文摘The modulation of electrical properties of MoS_2 has attracted extensive research interest because of its potential applications in electronic and optoelectronic devices.Herein,interfacial charge transfer induced electronic property tuning of MoS_2 are investigated by in situ ultraviolet photoelectron spectroscopy and x-ray photoelectron spectroscopy measurements.A downward band-bending of MoS_2-related electronic states along with the decreasing work function,which are induced by the electron transfer from Cs overlayers to MoS_2,is observed after the functionalization of MoS_2 with Cs,leading to n-type doping.Meanwhile,when MoS_2 is modified with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane(F_4-TCNQ),an upward band-bending of MoS_2-related electronic states along with the increasing work function is observed at the interfaces.This is attributed to the electron depletion within MoS_2 due to the strong electron withdrawing property of F_4-TCNQ,indicating p-type doping of MoS_2.Our findings reveal that surface transfer doping is an effective approach for electronic property tuning of MoS_2 and paves the way to optimize its performance in electronic and optoelectronic devices.
基金financially supported in part by National Key R&D Program of China(Nos.2020YFA0406103,2017YFA0207301)National Natural Science Foundation of China(Nos.21725102,91961106,U1832156,22075267,21803002)+4 种基金Science and Technological Fund of Anhui Province for Outstanding Youth(No.2008085J05)Youth Innovation Promotion Association of CAS(No.2019444)Young Elite Scientist Sponsorship Program by CAST,MOST(No.2018YFA0208603)Users with Excellence Program of Hefei Science Center CAS(No.2020HSC-UE003)Postdoc Matching Fund Scheme of the Hong Kong Polytechnic University(No.1-W144)。
文摘Anodic oxygen evolution reaction(OER)is the key bottleneck for water electrolysis technique owing to its sluggish reaction kinetics.Interfacial engineering on the rationally designed heterostructure can regulate the electronic states efficiently for intrinsic activity improvement.Here,we report a co-phosphorization approach to construct a VPO_(4)-Ni_(2)P heterostructure on nickel foam with strongly chemical binding,wherein phosphate acts as electronic modifier for Ni_(2)P electrocatalyst.Profiting from the interfacial interaction,it is uncovered that electron shifts from Ni_(2)P to VPO_(4)to render valence increment in Ni species.Such an electronic manipulation rationalizes the chemical affinities of various oxygen intermediates in OER pathway,giving a substantially reduced energy barrier.As a result,the advanced VPO_(4)-Ni_(2)P heterostructure only requires an overpotential of 289 mV to deliver a high current density of 350 mA/cm^(2)for OER in alkaline electrolyte,together with a Tafel slope as low as 28 mV/dec.This work brings fresh insights into interfacial engineering for advanced electrocatalyst design.
基金the National Key Research and Development Program of China(Nos.2022YFB3803600 and 2018YFB1502001)National Natural Science Foundation of China(Nos.22238009,51932007,U1905215,52073223,52173065,and 52202375)+2 种基金the Natural Science Foundation of Hubei Province of China(No.2022CFA001)China Postdoctoral Science Foundation(Nos.2021TQ0311 and 2021M702990)International Postdoc-toral Exchange Fellowship Program(No.PC2022051).
文摘Electron donors(EDs)are widely used to improve the H 2 production performance of Schottky junction photocatalysts,but the functions of EDs are still unknown from the perspective of electron transfer dy-namics.Herein,Pt nanocluster-decorated CdS nanorod is successfully prepared to construct a typical CdS/Pt Schottky junction.Pt nanoclusters with a diameter of∼2 nm are deposited on the surface of CdS nanorods by in situ photoreduction at sub-zero temperature.The CdS/Pt photocatalyst using lactic acid shows a higher H_(2)production rate of 4762μmol g^(-1)h^(-1)compared to that using methanol,tri-ethanolamine,and glycerol.To understand the cause,the dynamics of photogenerated carriers in CdS/Pt photocatalysts during ED-assisted H_(2)production are revealed by femtosecond transient absorption spec-troscopy.Among the four organic EDs,lactic acid enables the fastest electron transfer rate of 1.8×10^(9)s^(-1)and the highest electron transfer efficiency of 76%at the CdS/Pt interface due to the most efficient hole consumption.This work sheds light on the importance of efficient interfacial electron transfer for im-proving the photocatalytic performance of Schottky junction photocatalysts.
文摘Constructing step-scheme(S-scheme)heterojunctions can considerably facilitate separation and transfer of photocarriers,as well as promote strong redox ability.The interface resistance of heterojunctions immediately affects photocarrier separation and determines the photocatalytic activity.Herein,we constructed a novel Bi OBr/Ni_(2)P/g-C_(3)N_(4) heterojunction using Ni_(2)P as a novel electron bridge to reduce the interfacial resistance of photocarriers between Bi OBr and g-C3N4.The as-prepared 10% BiOBr/Ni2P/g-C_(3)N_(4) sample exhibited outstanding visible-light photocatalytic performance for methyl orange and rhodamine B removal,with degradation efficiencies of 91.4% and 98.9%,respectively.The excellent photocatalytic activity of Bi OBr/Ni_(2)P/g-C_(3)N_(4) was mainly attributed to the synergistic effects of the Ni2P cocatalyst and S-scheme heterojunction,which not only reduced the interface resistance but also retained the strong redox potential of the photocarriers.In addition,the formation of the S-scheme system was supported by active oxygen species investigation,current-voltage curves,and density functional theory calculations.This work provides a guideline for the design of highly efficient S-scheme photocatalysts with transition metal phosphates as electron bridges to improve photocarriers separation.
基金supported by the National Natural Science Foundation of China (21721003,22202080 and 22034006)。
文摘The slow water dissociation is the rate-determining step that slows down the reaction rate in alkaline hydrogen evolution reaction(HER).Optimizing the surface electronic structure of the catalyst to lower the energy barrier of water dissociation and regulating the binding strength of adsorption intermediates are crucial strategy for boosting the catalytic performance of HER.In this study,RuO_(2)/BaRuO_(3)(RBRO)heterostructures with abundant oxygen vacancies and lattice distortion were in-situ constructed under a low temperature via the thermal decomposition of gel-precursor.The RBRO heterostructures obtained at 550℃ exhibited the highest HER activity in 1 M KOH,showing an ultra-low overpotential of 16 mV at 10 mA cm^(-2)and a Tafel slope of 33.37 m V dec^(-1).Additionally,the material demonstrated remarkable durability,with only 25 mV of degradation in overpotential after 200 h of stability testing at 10 mA cm^(-2).Density functional theory calculations revealed that the redistribution of charges at the heterojunction interface can optimize the binding energies of H*and OH*and effectively lower the energy barrier of water dissociation.This research offers novel perspectives on surpassing the water dissociation threshold of alkaline HER catalysts by means of a systematic design of heterogeneous interfaces.
基金financially supported by the National Natural Science Foundation of China(Nos.U180413,11904084,and U2004212)Center for Outstanding Overseas Scientists(No.GZS2023007).
文摘Molecular catalysts with well-defined single atom sites and coordination environments exhibit significant potential as oxygen reduction electrocatalysts,but suffering from the activity and stability issues.Herein,the ultrathin carbon shell supported FePc molecule electrocatalysts(FePc/TA-ONG-N),featuring with a direct oxygen bridging between FePc and carbon substrate,were designed and synthesized.The direct connection with oxygen atom on carbon substrate,certified by the Fourier transform infrared spectroscopy(FTIR)and extended X-ray absorption fine structure(EXAFS),can remarkably enhance the interaction and facilitate electron transfer from Fe,leading to an improved activity by reducing adsorption strength of intermediate species through lowering the d-band center position.The resultant half-wave potential of 0.902 V together with a Tafel slope of 23.64 mV·dec^(−1)is superior to Pt/C and control samples.Such catalyst holds a promise as air-cathode electrocatalyst in Zn-air battery with excellent operation stability exceeding 80 h.The density functional theory(DFT)calculations and molecular dynamic simulations unveiled that the O-bridge can effectively stabilize the FePc molecule and function as electron buffer to donate/gain electrons to/from Fe atom during the adsorption of oxygenates.The current findings are insightful for developing molecular catalysts with high performance through substrate engineering and axial coordination.
基金supported by the National Science Foundation (CHE-0848556)the donors of the Petroleum Research Fund of the American Chemical Society (PRF #49286-ND6)
文摘The interracial electron transfer （IET） dynamics of single CdSe core/multilayer shell （CdS2MLZnCdS1MLZnSIML） quantum dots （QDs） on the （110） surface of a futile TiO2 single crystal and TiO2 nanoparticles have been compared. The fluorescence decay rates of single QDs on TiO2 are faster than those on glass, an insulating substrate, due to lET from the QDs to TiO2. Whereas the average IET rates are similar for QDs on the single crystal and nanoparticles, the distribution of lET rates is much broader in the latter, indicating a broad distribution of QD adsorption sites on the TiO2 nanoparticles.
基金supported by National Natural Science Foundation of China(U23A20102,52202375,22469001)the Natural Science Foundation of Hubei Province of China(2022CFA001).
文摘Pure ZnO exhibits low photocatalytic H_(2)O_(2)production activity due to the rapid charge recombination.To realize the spatial separation of photogenerated electrons and holes,constructing an electron transfer channel on the ZnO surface is an effective approach.This study successfully modified the surface of ZnO using F^(-)(ZnO/F)by introducing NH4F in an aqueous phase photocatalytic system.The F^(-)is adsorbed on the ZnO surface by Coulombic force and significantly improves the photocatalytic H_(2)O_(2)production performance of ZnO,with the highest efficiency of 4137.2μmol,g·^(-1)·L^(-1)·h^(-1).The photocatalytic performance enhancement mechanism of ZnO/F is explained in terms of electron transfer dynamics by femtosecond transient absorption spectroscopy(fs-TAS)measurements.F^(-)surface modification constructs a new ultrafast electron transport pathway from the ZnO CB to F^(-),and the optimal ZnO/F exhibits the fastest interfacial electron transfer lifetime of 5.8 ps.The F^(-)surface modification effectively facilitates the charge separation,thereby increasing the number of electrons available for photocatalytic H_(2)O_(2)reaction.This study has revealed the roles of F^(-)surface modification in the photocatalytic H_(2)O_(2)production by ZnO and provides guidance for ionic modification to improve photocatalytic performance.
基金supported by the National Natural Science Foundation of China(92061201,21825106 and 22102155)the China Postdoctoral Science Foundation(2021M692909 and 2022T150587)+1 种基金the Thousand Talents(Zhongyuan Scholars)Program of Henan Province(234000510007)the Guangdong Basic and Applied Basic Research Foundation(2023A1515140180)。
文摘Electrochemical biomass oxidation has garnered considerable attention due to its low energy consumption and the production of high-value chemicals.Supported metal nanoparticle catalysts have been widely explored in electrochemical 2,5-hydroxymethylfurfural oxidation reaction(HMFOR)but limited by their inhomogeneity to build a clear structure-ability relationship at atomic level.Atomically precise metal nanoclusters with well-defined composition,high purity and unique physichemical property are one kind of ideal model electrocatalyst.In this work,we regulate the microenvironment of catalytic sites in Ni Se_(2)utilizing atomically precise and charge tunnable Au_(25)nanoclusters.The electrochemical results reveal that after the modification of Au_(25)nanoclusters,the HMFOR ability of NiSe_(2)could be enhanced.Among them,the NiSe_(2)modified with Au_(25)^(-)clusters displayed the best electrocatalytic ability,in which the electrons were preferred to transfer from Au_(25)^(-)to NiSe_(2)substrate resulting in the electrons accumulation at the electrocatalyst surface.The enhanced electrochemical performance of electrocatalyst can be attributed to two key factors:(1)enhanced adsorption ability towards HMF due to the strong interaction between electron enriched surface and electrophilic furan rings;(2)fast electron transfer at Au_(25)^(-)/NiSe_(2)interface,resulting in the rapid structure evolution to form active Ni OOH sites.This study serves as a valuable reference for designing highly efficient,atomically precise metal nanocluster electrocatalysts for biomass upgrading.
基金the National Key Research and Development Program of China(No.2021YFA0910400)the National Natural Science Foundation of China(Nos.21605110 and 21972102)+1 种基金Natural Science Research Foundation of Jiangsu Higher Education Institutions(Nos.19KJB150038 and 21KJB180018)Natural Science Foundation of Suzhou University of Science and Technology(Nos.XKQ2018014 and XKZ2019011)。
文摘Pore structure plays critical roles in electrode kinetics but very challenging to tailor porous nanowires with rationally distributed pore sizes in a bioelectrochemical system.Herein a hierarchically porous nanowires-material is delicately tuned for an optimal pore structure by adjusting the weight percentage of SiO_(2)-hard template in an electrospinning precursor solution.The asprepared optimal electrospinning nanowires further used as an anode of microbial fuel cells(MFCs),delivering a maximum output power density of 1,407.42 mW·m^(−2)with 4.24 and 10 times higher than that of the non-porous fiber and carbon cloth anode,respectively.The great enhancement is attributed to the rational pore structure which offers the largest surface area while the rich-mesopores well match with the size of electron mediators for a high density of catalytic centers.This work provides thoughtful insights to design of hierarchical porous electrode for high-performance MFCs and other bioelectrochemical system devices.
基金National Natural Science Foundation of China(Nos.22172185,21773285,and U1932128)CAS Western Youth Scholars Program(No.XAB2019AW09)+2 种基金Fund Program for the Scientific Activities of Selected Returned Overseas Professionals in Shanxi Province(No.20220051)CAS Pioneer“Hundred Talents Program”the Start-up Grant of Institute of Coal Chemistry for financial support。
文摘Photocatalytic mineralization of recalcitrant contaminants like phenol in wastewater requires abundant hydroxyl radicals(·OH) to initiate the reaction prior to the ring-opening. We here increase the free energy for adsorption of O~* species on TiOsurface and slightly downshift the band position by tin doping. This can simultaneously promote the generation and suppress the annihilation of ·OH. Besides, tin doping can also facilitate semiconductor-cocatalyst-solution(SCS) interfacial electron transfer by lowering the potential barrier and synergistically enhance the photon utilization. By filming the photocatalyst onto our developed fixed bed reactors, the loss of photons resulting from undesirable absorption by contaminants can be alleviated. By these virtues, trace amount of phenol in wastewater can be efficiently mineralized.
