Intimate understanding of the synthesis-structure-activity relationships is an accessible pathway to overcome the intrinsic challenges of carbon nitride(g-C_(3)N_(4))photocatalysts.This work looks in the effects of hu...Intimate understanding of the synthesis-structure-activity relationships is an accessible pathway to overcome the intrinsic challenges of carbon nitride(g-C_(3)N_(4))photocatalysts.This work looks in the effects of humidity of the synthesis process to the morphology,chemical structure,band structure as well as the photocatalytic activity of g-C_(3)N_(4) materials.Four g-C_(3)N_(4) samples were prepared by heating melem in four gas environments:dry Ar,dry Air,moist Ar and moist Air.The photocatalytic activity measurements revealed that the samples synthesized in moist inert and oxidic gases environments displayed 20 and 10 times the photocata lytic H_(2) evolution activity of the samples synthesized in dry inert and oxidic gases environments,respectively.The reasons for this remarkable variety in photocata lytic activities had been through investigated.After all,the terminations of the carbon vacancies were identified as the dominant factor in enhancing H_(2) evolution performance.The work here thus demonstrating an example of defect engineering.展开更多
Expanding the optical absorption range of photocatalysts is still a key endeavor in graphitic carbon nitride(g-C_(3)N_(4))studies.Here,we report on a novel thiophene group extending the optical property,which is assig...Expanding the optical absorption range of photocatalysts is still a key endeavor in graphitic carbon nitride(g-C_(3)N_(4))studies.Here,we report on a novel thiophene group extending the optical property,which is assigned to n-π^(*)electronic transitions involving the two lone pairs on sulfur(TLPS).The as-prepared samples,denoted as CN-ThAx(where x indicates the amount of ThA added,mg),showed an additional absorption above 500 nm as compared to pristine g-C_(3)N_(4).Further,the thiophene group enhanced charge carrier separation to suppress e‒/h+pair recombination.The experimental results suggest that the thiophene group can obstruct the polymerization of melem to generate a large plane,thus exposing the lone electron pairs on the sulfur.The photocatalytic activity was evaluated in the decomposition of bisphenol A and H2 evolution.Compared with g-C_(3)N_(4),the optimized CN-ThA_(30) sample led to a 6.6-and 2-fold enhancement of the degradation and H2 generation rates,respectively.The CN-ThA_(30) sample allowed for synchronous H2 production and BPA decomposition.展开更多
The crystal phases are essential to the physicochemical properties and functionalities of materials.Copper selenide has emerged as an important and appealing semiconductor,which can exist in a variety of polymorphic p...The crystal phases are essential to the physicochemical properties and functionalities of materials.Copper selenide has emerged as an important and appealing semiconductor,which can exist in a variety of polymorphic phases.However,the richness of polymorphs also makes it a challenge to the direct preparation of copper selenide nanocrystals with tunable phases.Herein,two polymorphs,that is,quasitetragonal Cu2−xSe nanocubes and metastable wurtzite Cu2Se nanodisks,are successfully synthesized by using a single precursor,copper(I)selenocyanate(CuSeCN),as the Cu and Se sources.The key to phase modulation is the optimal choice of the ligand in the synthesis.The as‐prepared nanocrystals possess different morphologies and compositions,giving rise to distinct optical properties and electrical conductivities.Interestingly,the copper selenide nanocrystals can provide a platform for the rational construction of two types of amorphous hollow Au─Cu─Se nanostructures by reaction with Au(I)precursor,in which their final shapes are well kept as that of the original nanocrystal templates.This work provides an easy strategy for the phase‐controlled synthesis of copper selenide nanocrystals and enables the design of new materials for broad applications.展开更多
基金financially supported by the National Natural Science Foundation of China(No.21777063,21676128)The Natural Science Foundation of Jiangsu Province(BK20180887)+1 种基金a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions,High-tech Research Key Laboratory of Zhenjiang(SS2018002)The High Performance Computing Platform of Jiangsu University。
文摘Intimate understanding of the synthesis-structure-activity relationships is an accessible pathway to overcome the intrinsic challenges of carbon nitride(g-C_(3)N_(4))photocatalysts.This work looks in the effects of humidity of the synthesis process to the morphology,chemical structure,band structure as well as the photocatalytic activity of g-C_(3)N_(4) materials.Four g-C_(3)N_(4) samples were prepared by heating melem in four gas environments:dry Ar,dry Air,moist Ar and moist Air.The photocatalytic activity measurements revealed that the samples synthesized in moist inert and oxidic gases environments displayed 20 and 10 times the photocata lytic H_(2) evolution activity of the samples synthesized in dry inert and oxidic gases environments,respectively.The reasons for this remarkable variety in photocata lytic activities had been through investigated.After all,the terminations of the carbon vacancies were identified as the dominant factor in enhancing H_(2) evolution performance.The work here thus demonstrating an example of defect engineering.
文摘Expanding the optical absorption range of photocatalysts is still a key endeavor in graphitic carbon nitride(g-C_(3)N_(4))studies.Here,we report on a novel thiophene group extending the optical property,which is assigned to n-π^(*)electronic transitions involving the two lone pairs on sulfur(TLPS).The as-prepared samples,denoted as CN-ThAx(where x indicates the amount of ThA added,mg),showed an additional absorption above 500 nm as compared to pristine g-C_(3)N_(4).Further,the thiophene group enhanced charge carrier separation to suppress e‒/h+pair recombination.The experimental results suggest that the thiophene group can obstruct the polymerization of melem to generate a large plane,thus exposing the lone electron pairs on the sulfur.The photocatalytic activity was evaluated in the decomposition of bisphenol A and H2 evolution.Compared with g-C_(3)N_(4),the optimized CN-ThA_(30) sample led to a 6.6-and 2-fold enhancement of the degradation and H2 generation rates,respectively.The CN-ThA_(30) sample allowed for synchronous H2 production and BPA decomposition.
基金National Natural Science Foundation of China,Grant/Award Number:21871129。
文摘The crystal phases are essential to the physicochemical properties and functionalities of materials.Copper selenide has emerged as an important and appealing semiconductor,which can exist in a variety of polymorphic phases.However,the richness of polymorphs also makes it a challenge to the direct preparation of copper selenide nanocrystals with tunable phases.Herein,two polymorphs,that is,quasitetragonal Cu2−xSe nanocubes and metastable wurtzite Cu2Se nanodisks,are successfully synthesized by using a single precursor,copper(I)selenocyanate(CuSeCN),as the Cu and Se sources.The key to phase modulation is the optimal choice of the ligand in the synthesis.The as‐prepared nanocrystals possess different morphologies and compositions,giving rise to distinct optical properties and electrical conductivities.Interestingly,the copper selenide nanocrystals can provide a platform for the rational construction of two types of amorphous hollow Au─Cu─Se nanostructures by reaction with Au(I)precursor,in which their final shapes are well kept as that of the original nanocrystal templates.This work provides an easy strategy for the phase‐controlled synthesis of copper selenide nanocrystals and enables the design of new materials for broad applications.
