新型金属-有机骨架基Z型光催化产氢材料的合成及性能研究

Semiconductor-mediated photocatalysis has been considered as a promising approach towards hydrogen production from water splitting. However, the conventional inorganic semiconductor-based photocatalysts suffer from low conversion efficiency. Metal frameworks (MOF) exhibit the similar hybrid structure as the natural photosynthesis system. And the photogenerated electrons show very negative potential, which is beneficial for water splitting to produce hydrogen fuel. Thus a great deal of effort has been focused on MOF-based photocatalysts. This proposal aims to fabricate a novel Z-scheme photocatalysts by using Ti-MOF as the photocathodes. WO3、BiVO4、Bi2MoO6、BiFeO3 serve as photoanodes. With the assistance of redox couple (Fe2+/Fe3+), the proposed Z-scheme photocatalysts present very high theoretical photocatalytic efficiency. Four different Z-systems, including separated Z-scheme films, composite Z-scheme films, separated Z-scheme powders and composite Z-scheme powders, will be fabricated. The corresponding photocatalytic hydrogen production efficiency will be studied. The effect of materials structure, band gap match and experimental conditions on the photocatalytic activity will be investigated. And the photocatalysis mechanism will be studied in details. This project may provide an ideal candidate for energy-related applications.

半导体光催化技术在太阳能光解水制氢领域已展现出巨大发展潜力，然而以无机半导体材料为主的传统光催化剂产氢效率很低。金属-有机骨架材料（MOF）由于具有与光合作用体系类似的金属-有机杂化结构，且光生电子电势较负，因此MOF光催化材料引起越来越多的研究关注。本研究提出构建以Ti基MOF为光阴极的Z型光催化产氢材料，选用WO3、BiVO4、Bi2MoO6、BiFeO3为光阳极材料，在氧化还原介质（Fe2+/Fe3+）辅助下实现高效光催化分解水产氢。采用电化学、水热及微波等方法合成四种不同形态的Z型体系，包括分离式MOF基Z型薄膜、复合式MOF基Z型薄膜、分离式MOF基Z型粉体、复合式MOF基Z型粉体材料。研究各类材料的光催化产氢性能，揭示光催化效率与材料结构、能带匹配及实验条件等因素的关系，探索控制合成MOF基Z型光催化材料的实验方法，深入研究光催化机理，为推动光催化材料在能源领域的应用做出贡献。

金属-有机骨架材料（MOF）具有与天然光合作用体系类似的金属-有机杂化结构，且其光生电子具有很负的还原电势，因而其在太阳能光解水制氢领域展现出巨大发展潜力。本研究以开发新型MOF基光催化产氢材料为主要研究目标，采用水热、原位化学沉积、高温固相等方法合成了染料敏化型MOF、MOF/CdS及MOF/g-C3N4等一系列MOF基复合光催化材料，采用扫描电镜、透射电镜、X射线衍射、XPS等分析手段对所合成的材料的结构和性能进行了系统分析，对于各类材料在可见光照射下光催化分解水产氢性能进行了深入研究。实验结果表明， MOF基复合材料在光电转换效率及光电化学稳定性等方面均表现出优异性能。此外，为了进一步拓展MOF型光催化材料，本项目还对传统光催化材料进行了改性，包括采用一步水热法合成了具有优异光催化性能的花状CuO颗；设计合成具有火柴状结构的ZnO/Au纳米线阵列，充分利用Au纳米颗粒的表面等离子体共振效应提高ZnO的光电催化性能；为今后进一步开发MOF基Z型光电催化材料相关器件，本课题还研究开发了具有超高的电化学性能及优异的稳定性的MnO2及CuO-PANI-rGO电容材料。综上，本项目较好地完成了项目预定目标，对于今后开发Z型光催化产氢材料具有一定的理论指导意义。