Crystallinity and crystal structure greatly influence the photocatalytic behavior of photocatalysts.Pristine g-C3N4 produced by traditional thermal-induced polycondensation reaction bears low crystallinity and thus po...Crystallinity and crystal structure greatly influence the photocatalytic behavior of photocatalysts.Pristine g-C3N4 produced by traditional thermal-induced polycondensation reaction bears low crystallinity and thus poor photoactivity,which originates from the incomplete polymerization of the precursor containing amine groups,abundant hydrogen bonds,and unreacted amino,as well as cyanide functional groups in the skeleton.During photocatalytic process,these residual functional groups often work as electron trap sites,which may hinder the transfer of electrons on the plane,resulting in low photoactivity.Fortunately,crystalline carbon nitride(CCN)was reported as a promising photocatalyst because its increased crystallinity not only reduces the number of carriers recombination centers,but also increases charge conductivity and improves light utilization due to extendedπ-conjugated systems and delocalizedπ-electrons.As such,we summarize the recent studies on CCN-based photocatalysts for the photoactivity enhancement.Firstly,the unique structure and properties of CCN materials are presented.Next,the preparation methods and modification strategies are well outlined.We also sum up the applications of CCN-based materials in the environmental purification and energy fields.Finally,this review concerning CNN materials ends with prospects and challenges in the obtainment of high crystallinity by effective techniques,and the deep understanding of photocatalytic mechanism.展开更多
基金the National Natural Science Foundation of China(Nos.52370109,22022608,21876113,22176127,21261140333,and 92034301)China Postdoctoral Science Foundation(No.2022M710830)+9 种基金Venture and Innovation Support Program for Chongqing Overseas Returnees(No.cx2022005)the Natural Science Foundation Project of CQ CSTC(No.CSTB2022NSCQ-MSX0035)National Key Research and Development Program of China(No.2020YFA0211004)the Shanghai Engineering Research Center of Green Energy Chemical Engineering(No.18DZ2254200)“111”Innovation and Talent Recruitment Base on Photochemical and Energy Materials(No.D18020)Shanghai Government(Nos.22010503400,18SG41,and YDZX20213100003002)Shanghai Sailing Program(No.22YF1430400)Research Project of Chongqing Education Commission Foundation(No.KJQN201800826)Science and Technology Research Program of Chongqing Municipal Education Commission of China(No.KJZD-K202100801)Post-doctoral Program Funded by Chongqing,and Chongqing University Innovation Research Group project(No.CXQT21023).
文摘Crystallinity and crystal structure greatly influence the photocatalytic behavior of photocatalysts.Pristine g-C3N4 produced by traditional thermal-induced polycondensation reaction bears low crystallinity and thus poor photoactivity,which originates from the incomplete polymerization of the precursor containing amine groups,abundant hydrogen bonds,and unreacted amino,as well as cyanide functional groups in the skeleton.During photocatalytic process,these residual functional groups often work as electron trap sites,which may hinder the transfer of electrons on the plane,resulting in low photoactivity.Fortunately,crystalline carbon nitride(CCN)was reported as a promising photocatalyst because its increased crystallinity not only reduces the number of carriers recombination centers,but also increases charge conductivity and improves light utilization due to extendedπ-conjugated systems and delocalizedπ-electrons.As such,we summarize the recent studies on CCN-based photocatalysts for the photoactivity enhancement.Firstly,the unique structure and properties of CCN materials are presented.Next,the preparation methods and modification strategies are well outlined.We also sum up the applications of CCN-based materials in the environmental purification and energy fields.Finally,this review concerning CNN materials ends with prospects and challenges in the obtainment of high crystallinity by effective techniques,and the deep understanding of photocatalytic mechanism.
