功能化有序介孔氮化碳材料的制备及其可见光光催化性能研究

Heterogeneous photocatalysis is an ideal green chemical technology for its unique properties, such as mild reacion condition, direct use of sunlight, short reation path, which show great application prospect in organic synthesis. However, large-scale applications remain limited by the low quantum efficiency in the photocatalytic process. In this project, a novel and effective functional visible-light photocatalyst would be designed by introduction of ordered mesoporous structure and loading noble metal into/onto graphitic carbon nitride catalysts, and be applied in photocatalytic conversion of alcohol to carbonyl compounds. The photocatalytic performance of the novel funtional photocatalysts would be investigated systematically.The composition, structure, optical absorption properties, the spatial structure and electron configuration of active centers, the adsorption behavior and chemical state of organic molecules on the surface of catalysts would be detailedly characterized. The effect of pore structure and noble metal particles on the seperation of electron-hole pair and interface migration, the formation of reactive oxygen species such as hydroxyl radicals on the catalyst surface would be fully studied, and the microscopic nature of pore structure and surface functions to promote process of photocatalytic oxidation would be clarified.The study would have great theroretical and practical signification in the development of novel visible-light photocatalysts and promoting large-scale application of photocatalytic technology in chemical synthesis.

多相光催化以其反应条件温和、可直接利用太阳光、反应路径短等独特性能而成为一种理想的绿色化学技术，在有机合成领域具有巨大的应用前景。针对光催化过程量子效率低而难以大规模应用的重大问题，本项目拟以环境友好的石墨相氮化碳为基体，通过引入有序介孔结构和对其进行表面贵金属改性修饰，从优化体相织构和表面功能改性两方面提高光催化效率，构建新型高效的可见光光催化剂，并应用于醇类光催化氧化合成羰基化合物；系统考察新型功能化催化剂的光催化性能；详细表征催化剂的组成、结构、光吸收特性、活性中心的空间结构与电子构型、有机物分子在催化剂表面的吸附行为和化学状态；研究孔结构和贵金属颗粒对光生电子-空穴对的分离及界面迁移、催化剂表面羟基自由基等活性氧物种的形成等影响，阐明孔结构和表面功能化促进光催化氧化过程的微观本质。本研究对开发新型可见光光催化剂、促进光催化技术在化学合成领域的规模化应用具有重大的理论和实际意义。

高效催化剂的设计开发是太阳光光催化技术的规模实际应用焦点和核心问题。本课题利用石墨相氮化碳具有独特的结构和电子特性, 通过多孔结构的引入、酸活化、以及贵金属修饰等多种方法对氮化碳材料进行改性，从优化体相织构和表面功能改性等方面提高光催化效率，构建新型可见光光催化材料，系统考察新型功能化催化剂的光催化性能，成功构建绿色、温和的反应体系，实现在低温、常压下对醇类化合物选择性氧化合成相应的羰基化合物、光催化降解废水中有机污染物；利用XRD、低温氮吸附、元素分析、FTIR、TEM、XPS 和紫外-可见漫反射光谱仪等分析手段对催化剂体相及表面结构进行详细表征，确定催化剂的结构、比表面积、孔结构、形貌、体相以及催化剂对不同波长光的吸收性能；通过研究自由基捕获剂对反应体系的影响研究多相催化反应过程中催化剂表面羟基自由基等活性氧物种。通过对氮化碳基催化剂中组成、结构和表面微观状态以及光催化性能的研究，建立催化剂的组成－结构－光催化性能之间的构效关系，指导高效光催化剂体系的构建。本课题的开展不仅对高效光催化剂的设计具有科学指导意义，对促进太阳光光催化技术在化学合成领域的大规模实际应用具有现实意义。