Construction of multi-channels of photo-carrier migration in photocatalysts is favor to boost conversion efficiency of solar energy by promoting the charge separation and transfer.Herein,a ternary ZnIn_(2)S_(4)/g-C_(3...Construction of multi-channels of photo-carrier migration in photocatalysts is favor to boost conversion efficiency of solar energy by promoting the charge separation and transfer.Herein,a ternary ZnIn_(2)S_(4)/g-C_(3)N_(4)/Ti_(3)C_(2) MXene hybrid composed of S-scheme junction integrated Schottky-junction was fabricated using a simple hydrothermal approach.All the components(g-C_(3)N_(4),ZnIn_(2)S_(4) and Ti_(3)C_(2) MXene)demonstrated two-dimensional(2D)nanosheets structure,leading to the formation of a 2D/2D/2D sandwich-like structure with intimate large interface for carrier migration.Furthermore,the photogenerated carriers on the g-C_(3)N_(4) possessed dual transfer channels,including one route in S-scheme transfer mode between the g-C_(3)N_(4) and ZnIn_(2)S_(4) and the other route in Schottky-junction between g-C_(3)N_(4) and Ti_(3)C_(2) MXene.Consequently,a highly efficient carrier separation and transport was realized in the ZnIn_(2)S_(4)/g-C_(3)N_(4)/Ti_(3)C_(2) MXene heterojunction.This ternary sample exhibited wide light response from 200 to 1400 nm and excellent photocatalytic H_(2) evolution of 2452.1μmol∙g^(–1)∙h^(–1),which was 200,3,1.5 and 1.6 times of g-C_(3)N_(4),ZnIn_(2)S_(4),ZnIn_(2)S_(4)/Ti_(3)C_(2) MXene and g-C_(3)N_(4)/ZnIn_(2)S_(4) binary composites.This work offers a paradigm for the rational construction of multi-electron pathways to regulate the charge separation and migration via the introduction of dual-junctions in catalytic system.展开更多
The practical applications of high-capacity alloy-type anode materials in sodium-ion batteries(SIBs)are challenged by their vast volume effects and resulting unstable electrode-electrolyte interphases during discharge...The practical applications of high-capacity alloy-type anode materials in sodium-ion batteries(SIBs)are challenged by their vast volume effects and resulting unstable electrode-electrolyte interphases during discharge-charge cycling.Taking red phosphorus(P)/carbon anode material as an example,we report an on-site conversion reaction to intentionally eliminate the volume effect-dominated surface P and yield an ionically conducting layer of Na3PS4solid-state electrolyte on the composite.Such a surface reconstruction can significantly suppress the electrode swelling and simultaneously enable the activation energy of interfacial Na+transfer as low as 36.7 k J mol^(-1),resulting in excellent electrode stability and ultrafast reaction kinetics.Consequently,excellent cycling performance(510 mA h g^(-1)at 5 A g^(-1)after 1000 cycles with a tiny capacity fading rate of 0.016%per cycle)and outstanding rate capability(484 mA h g^(-1)at 10 A g^(-1)are achieved in half cells.When coupled with Na_(3)V_(2)(PO4)3cathode,the full cells exhibit 100%capacity retention over 200 cycles at 5C with an average Coulombic efficiency of 99.93%and a high energy density of 125.5 W h kg^(-1)at a power density of 8215.6 W kg^(-1)(charge or discharge within~49 s).Remarkably,the full cell can steadily operate at a high areal capacity of 1.9 mA h cm^(-2),the highest level among red P-based full SIBs ever reported.展开更多
As a highly toxic heavy metal,Cr(VI)reduction by developing high-efficiency photocatalysts is of great significance.Herein,we firstly design few-layer Ti_(3)C_(2) MXene(FTM)by the hand-operated shaking,show-ing dual a...As a highly toxic heavy metal,Cr(VI)reduction by developing high-efficiency photocatalysts is of great significance.Herein,we firstly design few-layer Ti_(3)C_(2) MXene(FTM)by the hand-operated shaking,show-ing dual advantages of structural stability and more exposed reactive sites.Then,a refluxed process is performed to fabricate FTM/CaIn_(2)S_(4)(FTC) composites,where 2D CaIn_(2)S_(4)(CIS) nanoplates are closely con-nected with 2D FTM to form Schottky junction.The optimal 1-FTC with the FTM/CIS mass ratio of 1 wt.%exhibits the highest activity toward photocatalytic Cr(VI)reduction under visible light.It is well eluci-dated that the broadened light absorption range and promoted charge carrier separation rate induced by the introduction of FTM are responsible for improving photocatalytic activity of CIS.During Cr(VI)photoreduction,1-FTC possesses excellent photo-stability and reusability.The effects of catalyst mass,co-existing ions,water sources and pH values on the Cr(VI)photoreduction efficiency are investigated.Pho-togenerated•O_(2)^(−)and e−are the main radical species accounting for Cr(VI)photoreduction over 1-FTC.The photocatalytic mechanism along with Cr(VI)removal pathway is exploited.This work may provide some insights into constructing FTM-based Schottky junctions for the efficient water purification.展开更多
The separation efficiency of electrons and holes and the enhancement of the surface reductive reaction in the metal sulfide semiconductor photocatalysts are important factors in boosting photocatalytic H_(2)evolution ...The separation efficiency of electrons and holes and the enhancement of the surface reductive reaction in the metal sulfide semiconductor photocatalysts are important factors in boosting photocatalytic H_(2)evolution from water.The control of both interface morphology and the charge-carrier utilization of metal sulfide-based photocatalysts can effectively improve the separation efficiency of electrons and holes and increase the surface reaction active sites,which are considered to be effective methods to improve the photocatalytic activity of semiconductors.Here,the Ti_(3)C_(2)(Mxene)modified all-sulfide 2D/2D Sscheme heterojunction Ti_(3)C_(2)/Zn In_(2)S_(4)(ZIS)/CdS composite material was firstly synthesized by a two-step solvothermal method.The formation of all-sulfide S-scheme heterojunction improves the efficiency of electron-hole separation.The intimate 2D/2D van der Waals structure provides a strong interaction force and a large contact area to enhance charge transfer.The addition of 2D Ti_(3)C_(2)forms the accumulation layer,reducing the recombination of electrons and holes.Under the synergistic promotion,the highest hydrogen production of the prepared Ti_(3)C_(2)/ZIS/CdS composite photocatalyst could reach 8.93 mmol/h/g.This work not only enriches the photocatalytic systems through integrating the ohmic junction and the 2D/2D all-sulfide S-scheme heterojunction,but also provides a satisfactory design strategy for engineering interfacial morphology and charge-carrier utilization.展开更多
文摘Construction of multi-channels of photo-carrier migration in photocatalysts is favor to boost conversion efficiency of solar energy by promoting the charge separation and transfer.Herein,a ternary ZnIn_(2)S_(4)/g-C_(3)N_(4)/Ti_(3)C_(2) MXene hybrid composed of S-scheme junction integrated Schottky-junction was fabricated using a simple hydrothermal approach.All the components(g-C_(3)N_(4),ZnIn_(2)S_(4) and Ti_(3)C_(2) MXene)demonstrated two-dimensional(2D)nanosheets structure,leading to the formation of a 2D/2D/2D sandwich-like structure with intimate large interface for carrier migration.Furthermore,the photogenerated carriers on the g-C_(3)N_(4) possessed dual transfer channels,including one route in S-scheme transfer mode between the g-C_(3)N_(4) and ZnIn_(2)S_(4) and the other route in Schottky-junction between g-C_(3)N_(4) and Ti_(3)C_(2) MXene.Consequently,a highly efficient carrier separation and transport was realized in the ZnIn_(2)S_(4)/g-C_(3)N_(4)/Ti_(3)C_(2) MXene heterojunction.This ternary sample exhibited wide light response from 200 to 1400 nm and excellent photocatalytic H_(2) evolution of 2452.1μmol∙g^(–1)∙h^(–1),which was 200,3,1.5 and 1.6 times of g-C_(3)N_(4),ZnIn_(2)S_(4),ZnIn_(2)S_(4)/Ti_(3)C_(2) MXene and g-C_(3)N_(4)/ZnIn_(2)S_(4) binary composites.This work offers a paradigm for the rational construction of multi-electron pathways to regulate the charge separation and migration via the introduction of dual-junctions in catalytic system.
基金support from the National Natural Science Foundation of China(51976143)the Guangdong Key Areas Research and Development Program(2020B090904001 and 2019B090909003)。
文摘The practical applications of high-capacity alloy-type anode materials in sodium-ion batteries(SIBs)are challenged by their vast volume effects and resulting unstable electrode-electrolyte interphases during discharge-charge cycling.Taking red phosphorus(P)/carbon anode material as an example,we report an on-site conversion reaction to intentionally eliminate the volume effect-dominated surface P and yield an ionically conducting layer of Na3PS4solid-state electrolyte on the composite.Such a surface reconstruction can significantly suppress the electrode swelling and simultaneously enable the activation energy of interfacial Na+transfer as low as 36.7 k J mol^(-1),resulting in excellent electrode stability and ultrafast reaction kinetics.Consequently,excellent cycling performance(510 mA h g^(-1)at 5 A g^(-1)after 1000 cycles with a tiny capacity fading rate of 0.016%per cycle)and outstanding rate capability(484 mA h g^(-1)at 10 A g^(-1)are achieved in half cells.When coupled with Na_(3)V_(2)(PO4)3cathode,the full cells exhibit 100%capacity retention over 200 cycles at 5C with an average Coulombic efficiency of 99.93%and a high energy density of 125.5 W h kg^(-1)at a power density of 8215.6 W kg^(-1)(charge or discharge within~49 s).Remarkably,the full cell can steadily operate at a high areal capacity of 1.9 mA h cm^(-2),the highest level among red P-based full SIBs ever reported.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.51902282 and 12274361)the Qinglan Project of Jiangsu of China,the Natural Science Founda-tion of Jiangsu Province(No.BK20211361)the College Natural Science Research Project of Jiangsu Province(No.20KJA430004).
文摘As a highly toxic heavy metal,Cr(VI)reduction by developing high-efficiency photocatalysts is of great significance.Herein,we firstly design few-layer Ti_(3)C_(2) MXene(FTM)by the hand-operated shaking,show-ing dual advantages of structural stability and more exposed reactive sites.Then,a refluxed process is performed to fabricate FTM/CaIn_(2)S_(4)(FTC) composites,where 2D CaIn_(2)S_(4)(CIS) nanoplates are closely con-nected with 2D FTM to form Schottky junction.The optimal 1-FTC with the FTM/CIS mass ratio of 1 wt.%exhibits the highest activity toward photocatalytic Cr(VI)reduction under visible light.It is well eluci-dated that the broadened light absorption range and promoted charge carrier separation rate induced by the introduction of FTM are responsible for improving photocatalytic activity of CIS.During Cr(VI)photoreduction,1-FTC possesses excellent photo-stability and reusability.The effects of catalyst mass,co-existing ions,water sources and pH values on the Cr(VI)photoreduction efficiency are investigated.Pho-togenerated•O_(2)^(−)and e−are the main radical species accounting for Cr(VI)photoreduction over 1-FTC.The photocatalytic mechanism along with Cr(VI)removal pathway is exploited.This work may provide some insights into constructing FTM-based Schottky junctions for the efficient water purification.
基金supported by the Outstanding Youth Fund of Heilongjiang Province (JQ 2020B002)Guangxi Science and Technology Base and Talent Special Project (AD21075001)the Reform and Development Fund Project of Local University supported by the Central Government。
基金financially supported by the National Natural Science Foundation of China(Nos.21975084 and 51672089)the Ding Ying Talent Project of South China Agricultural University for their support。
文摘The separation efficiency of electrons and holes and the enhancement of the surface reductive reaction in the metal sulfide semiconductor photocatalysts are important factors in boosting photocatalytic H_(2)evolution from water.The control of both interface morphology and the charge-carrier utilization of metal sulfide-based photocatalysts can effectively improve the separation efficiency of electrons and holes and increase the surface reaction active sites,which are considered to be effective methods to improve the photocatalytic activity of semiconductors.Here,the Ti_(3)C_(2)(Mxene)modified all-sulfide 2D/2D Sscheme heterojunction Ti_(3)C_(2)/Zn In_(2)S_(4)(ZIS)/CdS composite material was firstly synthesized by a two-step solvothermal method.The formation of all-sulfide S-scheme heterojunction improves the efficiency of electron-hole separation.The intimate 2D/2D van der Waals structure provides a strong interaction force and a large contact area to enhance charge transfer.The addition of 2D Ti_(3)C_(2)forms the accumulation layer,reducing the recombination of electrons and holes.Under the synergistic promotion,the highest hydrogen production of the prepared Ti_(3)C_(2)/ZIS/CdS composite photocatalyst could reach 8.93 mmol/h/g.This work not only enriches the photocatalytic systems through integrating the ohmic junction and the 2D/2D all-sulfide S-scheme heterojunction,but also provides a satisfactory design strategy for engineering interfacial morphology and charge-carrier utilization.
