新型钛基氧化物MTi5O11(M=Ca,Sr,Ba)物性调控及其光解水机理的研究

项目名称： 新型钛基氧化物MTi5O11(M=Ca,Sr,Ba)物性调控及其光解水机理的研究

项目编号： No.51472254

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 一般工业技术

项目作者： 张秋菊

作者单位： 中国科学院宁波材料技术与工程研究所

项目金额： 83万元

中文摘要： 降低制氢成本、发展氢经济是解决能源危机和环境恶化的有效途径之一，而利用半导体材料吸收太阳光分解水制氢也是一项涉及到多学科基础研究，具有挑战性的课题。经过科学家不断探索和积累，目前在寻找新型光催化材料以及对已有光催化材料进行改性方面已取得了一定的进步，但总体而言，光催化制氢的效率还很低，没有达到实际应用的要求。新型钛基氧化物MTi5O11(M=Ca, Sr, Ba)是一种结构稳定、禁带宽度适中、能对可见光响应的半导体材料。更重要的是该氧化物能促进水分解制氢，是一种潜在的、具有广阔应用前景的光催化材料。因此，对该材料结构和性质进行深入、细致的研究具有重要的意义。本项目将利用第一性原理计算对该类材料的热力学性质、电子结构以及光解水制氢催化机理等方面开展研究,并在此基础上进行同族元素掺杂、构建半导体异质结等理论设计，探索提高材料光催化性能的方法，为将来实验上对该材料开展深入研究和提高性能做理论。

中文关键词： 第一性原理；氧化物；界面/表面；光催化；水分解

英文摘要： Reducing the cost of hydrogen production to prompt the development of the hydrogen economy is the effective way to solve the problems of the energy crisis and the environment deterioration. Nevertheless, direct water splitting by semiconductor-based potocatalysts to produce hydrogen is a challenging subject, involving multidisciplinary integration and cooperation. Overall, much progress has been made in searching new candidates or improving the activity of the existing photocatalysts. However, the efficiency of hydrogen production is still rather low, which is far from the demand for industrialization. The novel Ti-based oxides MTi5O11 (M=Ca, Sr, Ba) could be potential and promising visible-light- responsive photocatalyst candidates, because of the geometrical stability, the moderate band gaps, more importantly, the capability of promotion spontaneous water-splitting to produce hydrogen. Therefore, thorough study on the structures and properties of the semiconductors is of great importance. In this proposal, we will perform the first-principles studies on the thermodynamical properties, electronic structures, and the mechanism of photocatalysis of MTi5O11 (M=Ca, Sr, Ba), followed by mixing the alkaline-earth elements on the M sites of MTi5O11 (M=Ca, Sr, Ba) and composing heterogeneous junctions with MTi5O11 (M=Ca, Sr, Ba) and TiO2 (Bronze) to improve the photocatalytic activity. The theoretical studies could provide support for the relevant experiments in the future.

英文关键词： first-principles;oxides;interface/surface;photocatalysis;water-splitting