卟啉修饰g-C_(3)N_(4)提高光催化产氢活性研究  

Porphyrin-modified g-C_(3)N_(4)to Enhance the Photocatalytic HydrogenProduction Activity

作　　者：魏婧宇 刘利 卢金荣 WEI Jing-yu;LIU Li;LU Jin-rong(College of Chemical Engineering,North China University of Science and Technology,Tangshan 063210,China)

机构地区：[1]华北理工大学化学工程学院,河北唐山063210

出　　处：《分子催化》2023年第5期439-451,I0001,共14页Journal of Molecular Catalysis(China)

基　　金：河北省高等学校科学技术研究项目资助(No.BJ2020009)。

摘　　要：半导体光催化制氢是一种可实现持续制备和储存氢气的绿色技术.石墨相氮化碳(g-C_(3)N_(4))是研究广泛的光催化剂,但其仍存在光利用率低、光生电子和空穴易复合等问题,制约着光催化产氢的性能.利用给电子卟啉修饰g-C_(3)N_(4),构建了四(4-羧基)苯基卟啉(TCPP)以共价/非共价方式修饰g-C_(3)N_(4)的催化剂.卟啉共价修饰g-C_(3)N_(4)(gC_(3)N_(4)-TCPP0.1)及非共价复合结构(TCPP0.1/g-C_(3)N_(4))光催化产氢速率分别为6 997和5 399μmol·g^(-1)·h^(-1),较g-C_(3)N_(4)分别提高了53%和18%. TCPPx/g-C_(3)N_(4)异质结加强了界面接触,促进了电荷转移,增强了可见光吸收能力,进而提高了光催化制氢性能. g-C_(3)N_(4)-TCPPx中, TCPP的接枝拓展了共轭结构,优化了电子结构,增大了分子偶极,促进了电荷分离,共价桥键为电荷传输提供了通道.Semiconductor photocatalytic hydrogen production is a strategy that allows for the sustainable preparation and storage of hydrogen.Graphitic carbon nitride(g-C_(3)N_(4))is a widely studied photocatalyst,but there are still problems such as low light utilisation and the tendency for photo-generated electrons and holes to compound,which limit the activity of photocatalytic hydrogen production.Two catalysts for the modification of gC_(3)N_(4) by tetra(phenylcarboxy)porphyrin(TCPP)in a covalent/non-covalent manner was constructed using electrondonating porphyrins.The morphological structure,photovoltaic properties,photocatalytic hydrogen production performance and charge transfer mechanism of the two catalysts have been investigated.The photocatalytic hydrogen production efficiency of the porphyrin covalently modified g-C_(3)N_(4)(g-C_(3)N_(4)-TCPP0.1)and the noncovalent composite structure(g-C_(3)N_(4)/TCPP0.1)were 6997 and 5399μmol·g−1·h−1,respectively,which were 53%and 18%higher than g-C_(3)N_(4).The g-C_(3)N_(4)/TCPPx heterojunction enhances interfacial contact,promotes charge transfer and enhances visible light absorption,thereby improving photocatalytic hydrogen production performance.The grafting of TCPP in g-C_(3)N_(4)-TCPPx expands the conjugate structure,optimizes the electronic structure,increases the molecular dipole,promotes charge separation,and covalent bridging bonds provide a channel for charge transport.

关 键 词：g-C_(3)N_(4) 卟啉 共价修饰 非共价修饰 光催化制氢 

分 类 号：O643[理学—物理化学]