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
Polymer solar cells(PSCs)consisting of a polymer donor and a small molecular acceptor is a promising photovoltaic technology,whose device performance is determined by both polymer donor and small molecular acceptor.Ha...Polymer solar cells(PSCs)consisting of a polymer donor and a small molecular acceptor is a promising photovoltaic technology,whose device performance is determined by both polymer donor and small molecular acceptor.Halogen atoms such as fluorine or chlorine atoms were usually introduced onto the polymer donors to downshift the highest occupied molecular orbital(HOMO)energy levels and improve the open-circuit voltage(VOC)of the PSCs.However,the introduction of the halogen atoms especially fluorine atoms greatly complicates the polymer synthesis.Herein,we report the use of a structural simple and easily synthesized building block,3,4-dicyanothiophene(DCT),to construct a set of halogen-free polymer donors PBCNTx(x=25,50,75)via ternary random copolymerization.The introduction of DCT units not only simplified the synthesis,but also downshifted the HOMO energy levels of the polymers and improved the V_(OC) of PSCs effectively.Encouragingly,the PBCNT75 afforded a power conversion efficiency up to 15.7%with a V_(OC) of 0.83 V,which are among the top values for halogen-free polymer donors.This work shows that the introduction of DCT units is a simple yet effective strategy to construct halogen-free and low-cost polymer donors for high-performance PSCs.展开更多
Perylene-3,4-(dicarboxylic monoimide)-9,10-(dicarboxylic monoanhydrate)(PIA)is one key intermediate to construct functionalized perylene diimides(PDIs)for various applications.However,the difficulty in synthesizing ch...Perylene-3,4-(dicarboxylic monoimide)-9,10-(dicarboxylic monoanhydrate)(PIA)is one key intermediate to construct functionalized perylene diimides(PDIs)for various applications.However,the difficulty in synthesizing chlorinated PIA hinders the study of chlorinated PDIbased materials.Although chlorination has been widely used to modify the properties of organic semiconductors.We successfully synthesize chlorinated PIA via a simple hydrolysis reaction using LiOH as the base,then a PDI dimer connected at the imide position,N-di-PDI-4Cl,is synthesized as an application example of chlorinated PIA.The heavily chlorinated PDI dimer exhibits deeper energy levels,slightly blue-shifted UV-Vis absorption compared to the non-chlorinated analogue.In addition,the photovoltaic performance of N-di-PDI-4Cl is characterized.This study paves one easy way to synthesize chlorinated PIA and its more delicate derivatives.展开更多
The recently emerged double-cable conjugated polymers have come into focus due to their significantly improved power conversion efficiencies (PCEs) in single-component organic solar cells (SCOSCs). In this work, the e...The recently emerged double-cable conjugated polymers have come into focus due to their significantly improved power conversion efficiencies (PCEs) in single-component organic solar cells (SCOSCs). In this work, the effect of chlorination in double-cable conjugated polymers with linear benzodithiophene backbone and pendant perylene bisimide on the photovoltaic performance in SCOSCs has been studied. After introducing chlorine atoms into conjugated side chains, the highest occupied molecular orbital level of the conjugated polymers is down-shifted, thus resulting in a higher open-circuit voltage. As a result, the chlorinated double-cable conjugated polymer exhibits improved photovoltaic performance from 3.46% to 3.57%.展开更多
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The work was financially supported by the Ministry of Science and Technology of China(Nos.2017YFA0206600 and 2019YFA0705900)the National Natural Science Foundation of China(Nos.21875072,U20A6002 and 51973169)+2 种基金Guangdong Innovative and Entrepreneurial Research Team Program(No.2019ZT08L075)This study also received financial support from Science and Technology Foundation of Guangdong Province(No.2021A0101180005)Special Projects in Key Areas for the University of Guangdong Province(No.2021ZDZX1009).
文摘Polymer solar cells(PSCs)consisting of a polymer donor and a small molecular acceptor is a promising photovoltaic technology,whose device performance is determined by both polymer donor and small molecular acceptor.Halogen atoms such as fluorine or chlorine atoms were usually introduced onto the polymer donors to downshift the highest occupied molecular orbital(HOMO)energy levels and improve the open-circuit voltage(VOC)of the PSCs.However,the introduction of the halogen atoms especially fluorine atoms greatly complicates the polymer synthesis.Herein,we report the use of a structural simple and easily synthesized building block,3,4-dicyanothiophene(DCT),to construct a set of halogen-free polymer donors PBCNTx(x=25,50,75)via ternary random copolymerization.The introduction of DCT units not only simplified the synthesis,but also downshifted the HOMO energy levels of the polymers and improved the V_(OC) of PSCs effectively.Encouragingly,the PBCNT75 afforded a power conversion efficiency up to 15.7%with a V_(OC) of 0.83 V,which are among the top values for halogen-free polymer donors.This work shows that the introduction of DCT units is a simple yet effective strategy to construct halogen-free and low-cost polymer donors for high-performance PSCs.
基金the National Natural Science Foundation of China(Nos.51973169,51703172 and 52273195)Key R&D program of Hubei Province(No.2021BAA014)+2 种基金the Natural Science Foundation of Hubei Province(No.2022CFB097)the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2020WNLOKF015)the science foundation of Wuhan Institute of Technology(No.K202025)。
文摘Perylene-3,4-(dicarboxylic monoimide)-9,10-(dicarboxylic monoanhydrate)(PIA)is one key intermediate to construct functionalized perylene diimides(PDIs)for various applications.However,the difficulty in synthesizing chlorinated PIA hinders the study of chlorinated PDIbased materials.Although chlorination has been widely used to modify the properties of organic semiconductors.We successfully synthesize chlorinated PIA via a simple hydrolysis reaction using LiOH as the base,then a PDI dimer connected at the imide position,N-di-PDI-4Cl,is synthesized as an application example of chlorinated PIA.The heavily chlorinated PDI dimer exhibits deeper energy levels,slightly blue-shifted UV-Vis absorption compared to the non-chlorinated analogue.In addition,the photovoltaic performance of N-di-PDI-4Cl is characterized.This study paves one easy way to synthesize chlorinated PIA and its more delicate derivatives.
基金the National Natural Science Foundation of China(Nos.51973169,51703172 and 52073016)the Open Project Program of Wuhan National Laboratory for Optoelectronics(No.2020WNLOKF015)the science foundation of Wuhan Institute of Technology(No.K202025).
文摘The recently emerged double-cable conjugated polymers have come into focus due to their significantly improved power conversion efficiencies (PCEs) in single-component organic solar cells (SCOSCs). In this work, the effect of chlorination in double-cable conjugated polymers with linear benzodithiophene backbone and pendant perylene bisimide on the photovoltaic performance in SCOSCs has been studied. After introducing chlorine atoms into conjugated side chains, the highest occupied molecular orbital level of the conjugated polymers is down-shifted, thus resulting in a higher open-circuit voltage. As a result, the chlorinated double-cable conjugated polymer exhibits improved photovoltaic performance from 3.46% to 3.57%.
