Yu Xiaohui, Xie Juan, Liu Qinqin, Dong Huilong, Li Youyong
Engineering Institute of Advanced Manufacturing and Modern Equipment Technology, Jiangsu University, Zhenjiang, Jiangsu 212013, China.
School of Materials Engineering, Changshu Institute of Technology, Changshu, Jiangsu 215500, China.
J Colloid Interface Sci. 2021 Jul;593:133-141. doi: 10.1016/j.jcis.2021.02.103. Epub 2021 Mar 9.
The oxide-based hybrid photocatalysts, especially TiO-based, have attracted tremendous attentions because of their prominent photocatalytic performance. Currently, theoretical understandings on the relationship between the interface of TiO-based heterostructures and their photocatalytic activity are still lacking. Here we systematically investigated the effects of interface structure on electronic properties of the g-CN/TiO heterostructure using density functional theory (DFT) calculation. The interaction between monolayer g-CN and TiO surface [with Anatase (101)/(001) facet] was explored, where a van der Waals heterojunction is formed. The presence of oxygen vacancy, nitrogen doping and hydrogen passivation on TiO surface is found to dramatically alter the electronic properties of g-CN/TiO heterostructure. Furthermore, the enhanced separation of electron - hole pairs and inhibited carrier recombination in the g-CN/TiO interface was analyzed based on the Bader charge analysis and charge density difference. The theoretical analysis revealed that oxygen vacancy and hydrogen passivation on TiO A001 surface induces the more significant charge separation, which may be the origin of enhanced photocatalytic efficiency of the g-CN/TiO heterostructures.
基于氧化物的杂化光催化剂，尤其是基于TiO的光催化剂，因其卓越的光催化性能而备受关注。目前，对于基于TiO的异质结构界面与其光催化活性之间的关系仍缺乏理论认识。在此，我们使用密度泛函理论（DFT）计算系统地研究了界面结构对g-CN/TiO异质结构电子性质的影响。探索了单层g-CN与TiO表面[锐钛矿（101）/（001）面]之间的相互作用，形成了范德华异质结。发现TiO表面存在氧空位、氮掺杂和氢钝化会显著改变g-CN/TiO异质结构的电子性质。此外，基于巴德电荷分析和电荷密度差分析了g-CN/TiO界面中电子-空穴对的增强分离和载流子复合的抑制。理论分析表明，TiO A001表面的氧空位和氢钝化诱导了更显著的电荷分离，这可能是g-CN/TiO异质结构光催化效率提高的原因。
