BiVO4/石墨烯异质界面的电子态与光催化性能研究

项目名称： BiVO4/石墨烯异质界面的电子态与光催化性能研究

项目编号： No.51302162

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 黄育红

作者单位： 陕西师范大学

项目金额： 25万元

中文摘要： 可再生能源的短缺和环境污染的恶化成为制约社会长远发展的重大问题，半导体光催化降解污染物或分解水制氢成为解决此类问题的重要途径之一。如何有效分离光生电子和空穴是提高半导体光催化剂量子产率和活性的关键。研究表明，利用半导体异质结的内建电场或能级差可达到这一目的，且已明确界面处带边偏移量的制约作用。然而，关于带边偏移量与界面结构及掺杂状态的关联关系仍不明朗。本项目拟以BiVO4/石墨烯异质结为例，计算分析界面能和界面键合状态，根据晶体对称性进行替位式掺杂，确定掺杂界面的稳定构型；考察其电子结构、态密度及吸收光谱的变化，探讨界面掺杂元素对带边偏移量的调控作用；制备典型界面取向及掺杂的异质结样品，基于PL光谱测量揭示异质结对电子-空穴对复合的抑制作用；进行光催化降解实验，结合理论分析，阐明BiVO4/石墨烯异质结对光催化特性增强的物理机制，为新型半导体光催化剂的设计提供参考。

中文关键词： BiVO4；纳米复合材料；电子态；能带结构；光催化

英文摘要： The shortage of renewable energy and deterioration of environmental pollution become two crucial issues restricting the sustainable development of society in the long-term future. Semiconductor photocatalysis which has potential applications in degradation of pollutants and water splitting is believed to be one of the main approaches to solve these two problems simultaneously. How to effectively separate the photo-induced electrons and holes is crucial to improve the quantum yield and catalytic activity. Previous investigations have illustrated that both the difference in band edge energy and the built-in electric field cross the semiconductor heterojuction can be used for that purpose, moreover, the band offset near the interface is dominant in the charge separation. However, the dependence of the band offset on the interface structure as well as the doping state is unclear. In this proposal, taking BiVO4/graphene heterojuction as an example, first-principle will be exploited to calculate and analyze the energy and bonding state of interface, according to the crystal symmetry, atoms at some typical lattice points will be substituted for interface doping, and stable interface configurations will be determined referencing to the energetics and bonding states. Based on this, the changes in the energy band structur

英文关键词： BiVO4；nano-composites；electronic states；energy band structure；photocatalysis