标题：Atomic Insights for Optimum and Excess Doping in Photocatalysis: A Case Study of Few-Layer Cu-ZnIn2S44
作者：Wang, Pengfei; Shen, Zhurui; Xia, Yuguo; Wang, Haitao; Zheng, Lirong; Xi, Wei; Zhan, Sihui
作者机构：[Wang, Pengfei; Wang, Haitao; Zhan, Sihui] Nankai Univ, Coll Environm Sci & Engn, Tianjin Key Lab Environm Remediat & Pollut Contro, MOE Key Lab Pollu 更多
通讯作者地址：[Zhan, SH]Nankai Univ, Coll Environm Sci & Engn, Tianjin Key Lab Environm Remediat & Pollut Contro, MOE Key Lab Pollut Proc & Environm Criteria, Tianj 更多
来源：ADVANCED FUNCTIONAL MATERIALS
关键词：atomic insights; few-layer nanosheets; optimum and excess doping;; photocatalysis
摘要：Herein, an example of Cu-doped few-layer ZnIn2S4 nanosheets is used to reveal the origin of optimum and excess doping for photocatalysts at atomic level. Results show that the metal-S-4 coordination maintains well with 0.5 wt% Cu substituted Zn atoms in the lattice. The introduced Cu atoms bring electronic acceptor states close to the valence band (VB) maximum and thus ensures higher charge density and efficient carrier transport, resulting in an optimum hydrogen evolution rate of 26.2 mmol h(-1) g(-1) and an apparent quantum efficiency of 4.76% at 420 nm. However, a distorted atomic structure and largely upshift of VB maximum with Cu-S-3.6 coordination are found with excess doping concentration (3.6 wt%). These bring the heavy charge recombination and consequentially dramatic reduced activity. This work provides a new insight into elemental doping study and takes an important step toward the development of ultrathin 2D photocatalysts.