期刊
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
卷 42, 期 15, 页码 9903-9913出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/j.ijhydene.2017.02.172
关键词
g-C3N4/TiO2 heterostructure; Electronic structure; Photocatalytic H-2 production; Density functional theory
资金
- National Natural Science Foundation of China [11447030, 51572219]
- Natural Science Foundation of Shaanxi Province of China [2016JQ1038, 2015JM1018]
- Scientific Research Program - Shaanxi Provincial Education Department of China [15JK1714]
- Science Foundation of Northwest University of China [14NW23]
- Double First-class University Construction Project of Northwest University
The electronic and optical properties of g-C3N4/TiO2 heterostructure are investigated using spin-polarized DFT+U calculations. The equilibrium spacing (1.94 angstrom) and binding energy (24 meV/angstrom(2)) show that g-C3N4/TiO2 is a van der Waals heterostructure. And the calculated band gap of g-C3N4/TiO2 is significantly reduced compared with TiO2. Therefore, the visible light response of g-C3N4/TiO2 heterostructure is remarkably improved. Besides, the predicted type II band alignment would ensure that the electrons can migrate from g-C3N4 monolayer to anatase TiO2 (101) surface, which leads oxidation and redox reactions can occur on g-C3N4 and TiO2, respectively. Finally, a built-in electric field within the interface region will be set. Above processes can benefit the separation of photoexcited carriers and enhance the hydrogen-evolution activity. In addition, compared with TiO2, g-C3N4/TiO2 with higher conduction band minimum energy can effectively produce higher-energy electrons to reduce hydrogen ions. Moreover, the influence of composite distance and the number of g-C3N4 layers are also investigated systematically. The results indicate that the optical absorption is enhanced over the whole spectrum with the increase of the number of g-C3N4 layers. Similar visible light enhancing is also found when the composite distance is decreased. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据