双金属有机骨架的设计、合成及光催化水氧化性能研究

Water oxidation reaction is the bottleneck of the light-driven water splitting process. The difficulties derive from the complexity of the water oxidation reaction itself that involves transfer of four protons and four electrons and the formation of O-O bond. In this proposal, the photocatalytic water oxidation system based on metal-organic framework containing photocatalyst and photosensitizer will be designed and systhesized through self-assembly of secondary building units. Electron transfer among water oxidation catalyst, photosensitizer, electron sacrificial acceptor will be studied. The relation between framework structure of metal-organic framework material and electron transfer or photocatalytic water oxidation will be investigated. The mechanism of photocatalytic water oxidation will be studied because of the merit of high crystallization of metal-organic framework by X-ray single crystal diffraction method. The results will provide some valuable information for the design of effective electron transfer of light-driven water oxidation system. It is possible to prepare photocatalytic water oxidation materials with the merit of high efficience, visible light response, and recyclable utilization. This proposal will pave the way for the preparation of new photocatalytic materials, as well as make great contribution to the mechanism of photocatalytic water oxidation.

水氧化反应是制约光解水应用的重要瓶颈之一。本研究拟采用次级结构单元自组装构筑含有光敏剂与催化剂的多孔金属有机骨架材料，研究电子在配位键连接的水氧化催化剂、光敏剂、电子牺牲性受体之间的传递机制，分析光催化水氧化反应的动力学行为，阐明金属有机骨架结构与电子传递、光催化水氧化反应等性能之间的构效关系。同时利用金属有机骨架的易结晶性，通过X-射线单晶衍射技术跟踪金属有机骨架反应过程中结构演变规律，探讨光催化水氧化机理，研究结果将为设计有效电子传递的光催化水氧化体系提供依据，从而获得具有高效、可见光响应、可循环利用、在光催化水氧化方面具有应用价值的光催化材料。本项目不仅为制备新型光催化材料提供有益的探索，也为光催化水氧化机理的研究提供实验基础。

水氧化反应是制约光解水应用的重要瓶颈问题，高效、稳定的催化剂是解决这一问题的关键因素。本项目构建了金属有机分子催化剂、无机纳米催化剂体系，并研究了各类催化剂的催化水氧化反应。本项目取得如下几点重要进展：（1）制备了含钴和铁过渡金属的金属有机分子催化剂，金属有机分子催化剂能够有效的光催化水氧化反应，催化性能优于Co3O4纳米材料。考察了光催化水溶液pH、光敏剂以及牺牲性受体的浓度对催化反应速率的影响。（2）制备了金属化合物无机纳米催化剂（NiCo2S4亚微米球、RuxSey/G），这些催化剂均表现出了有效的催化氧析出和氧还原性能，研究发现优异的电子传递能够有效提高催化剂的催化性能。（3）在本项目支持下，为未来发展高效光转化体系器件，研究了过渡金属化合物无机纳米催化剂对太阳能电池中氧化还原电对的催化活性，并考察了其催化机制，有效电极的构筑方法。同时还对制约新型钙钛矿电池器件效率的关键问题-钙钛矿的有效成膜问题进行了研究。本项目的顺利实施为太阳能的转化利用提供了一定的科学基础和材料基础。