宽光谱响应光催化剂分解水制氢的研究

Photocatalytic water splitting for hydrogen production is one of the most promising ways to solve crisis of energy and environment in the future, and photocatalyst with wide visible absorption and high quantumn efficiency is required in the view of commercial application.In the past decades, a great deal of work has been carried out in this field, but the quantumn efficiency of hydrogen production is still low for photocatalysts with wide visible absorption,because of the fact that the extended visible absorption accompanies with the decrease of driving force of carriers. Based on our recent work and previous literatures, this project is thus to focus on the photocatalytic water splitting on some novel oxysulfides and oxynitrides with ca. 600 nm absorption edge(denoted as"600 nm-class photocatalysts").The main research topics contain: i) controllable synthesis of photocatalysts with fine local structures; ii) fabrication of photocatalytic systems with high efficiency of carrier separation; iii) advanced charaterizations of photocatalysts; iv) high throughout tests of photocatalytic performances; v) theory calculation and spectrascopy analysis etc.. The purpose is to reveal basic principles of excitation and transfer of photogenerated carriers with relatively low driving force, and to set up efficient correlation between structure of catalyst and catalytic performance.New concepts or theories are expected to be developed, which will guide fabrication of the photocatalytic system with significantly enhanced quantumn efficiency of water splitting, and finally contribute to overall water splitting on the 600 nm-class photocatalysts.

光催化分解水制氢是从根本上解决能源及环境问题的理想途径之一，其中催化剂宽光谱响应和高效催化转化是其产业化的基本要求。然而, 催化剂吸收波长红移伴随着光生载流子驱动力下降，不利于载流子分离，导致目前宽光谱响应光催化剂分解水制氢量子效率仍然很低。基于文献和前期研究的工作基础，本项目拟以吸收带边至600 nm左右的硫氧化物和氮氧化物可见光催化剂(简称"600nm级光催化剂")为主要研究对象，以光催化材料的微观结构控制为切入点，通过高效光生电子-空穴分离体系构建、详细的催化剂结构表征、高通量光催化还原/氧化分解水半反应活性评测、理论计算及超快光谱分析等内容研究，揭示光生电子在较低驱动力情况下的激发、转移和表面反应等过程的基本规律，加深对600 nm光催化剂微观结构与制氢性能之间的"构效关系"认识，发展新的概念和方法，显著提高600 nm级光催化剂分解水制氢的量子效率，奠定其完全分解水制氢的基础。

太阳能作为最丰富的清洁可再生能源之一,其开发利用受到了世界范围内的广泛关注，通过半导体光催化分解水反应实现太阳能向清洁能源氢能的转化,是解决人类面临的能源和环境问题的理想途径之一，其中催化剂宽光谱响应和高效催化转化是其产业化的基本要求。然而, 催化剂吸收波长红移伴随着光生载流子驱动力下降，不利于载流子分离，导致目前宽光谱响应光催化剂分解水制氢量子效率仍然很低。本课题针对当前的研究现状以吸收带边至600nm左右的硫氧化物和氮氧化物具有可见光吸收的催化剂（简称“600nm级光催化剂”）为研究对象，项目主要进行了1）合成MgTa2O6-xNx, Ba(Mg1/3Ta2/3)O3−xNy,CoOx纳米团簇等多个新型的光催化材料和高效水氧化催化剂。2）通过异质结与表界面修饰构建高效光生电子-空穴分离体系，进而提升了产氢性能。3)设计构筑了多个Z机制全分解水研究体系，为拓宽Z机制全分解水体系提供了新策略。4）通过研究光催化剂与性能之间的“构效关系”，加深了相关理论认识等。研究结果具有创新性和科学意义。