增强π共轭结构的电子密度和面内电荷输运促进g-C_(3)N_(4)的光催化析氢  

Enhanced electron density of theπ-conjugated structure and in-plane charge transport to boost photocatalytic H_(2)evolution of g-C_(3)N_(4)

作　　者：张洋 曹宁 刘晓明 贺凤婷 郑彬 赵朝成 王永强 Yang Zhang;Ning Cao;Xiaoming Liu;Fengting He;Bin Zheng;Chaocheng Zhao;Yongqiang Wang(State Key Laboratory of Petroleum Pollution Control,China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]State Key Laboratory of Petroleum Pollution Control,China University of Petroleum(East China),Qingdao 266580,China

出　　处：《Science China Materials》2023年第6期2274-2282,共9页中国科学（材料科学（英文版）

基　　金：financially supported by the National Science and Technology Major Project(2016ZX05040003)。

摘　　要：石墨相氮化碳(g-C_(3)N_(4))已成为一种新兴的无金属光催化剂并引起了研究人员的关注.然而,通过传统热缩聚得到的纯g-C_(3)N_(4)(PCN)的庚烷环链聚合度低,含有大量的电荷重组中心,阻碍了平面内的电荷传输,导致光催化性能不理想.本文采用一水合草酸铵热处理PCN制备了高分散的多孔g-C_(3)N_(4)纳米片(CN-A),并在不引入杂原子的情况下,成功地提高了其平面内庚烷环链的完整度.电子顺磁共振和^(13)C核磁共振分析表明,π共轭结构的电子密度和离域效应显著提高.所制备的样品表现出优异的稳定性和光催化活性,在无助催化剂Pt和有助催化剂Pt下的氢气还原速率分别是PCN的11.2倍和5.3倍.Graphite carbon nitride(g-C_(3)N_(4))has become an emerging metal-free photocatalyst and attracted the attention of researchers.However,pure g-C_(3)N_(4)(PCN)prepared by traditional thermal condensation polymerization has a low polymerization of heptazine ring chains and a large number of charge recombination centers,which hinder in-plane charge transport,leading to undesirable photocatalytic performance.Herein,PCN fabrication by thermal treatment with ammonium oxalate monohydrate was performed to produce highly dispersed porous g-C_(3)N_(4)nanosheets,and the integrity of their in-plane heptazine ring chains was successfully improved without introducing heteroatoms.Electron paramagnetic resonance and^(13)C nuclear magnetic resonance analyses revealed significantly increased electron density and delocalization of theπ-conjugated structure.The obtained samples exhibited acceptable stability and photocatalytic activity,and the hydrogen reduction rates without and with the Pt co-catalyst were 11.2 and 5.3 times that of PCN.

关 键 词：电子顺磁共振 电子密度 石墨相氮化碳 离域效应 完整度 电荷输运 电荷传输 氢气还原 

分 类 号：TQ116.2[化学工程—无机化工] O643.36[理学—物理化学] O644.1[理学—化学]