g-C3N4增强铋基光催化材料的稳定性及其对有机污染物的降解研究

Bismuth-based photocatalysts posses high visible light photocatalytic activity, and they have wide application prospect in the organic removal by solar energy. However, the application is limited due to the serious photocorrosion of Bi-based photocatalysts in the process of photocatalytic reaction. Thus, in this project, on the basis of the photocorosion of Bi-based photocatalysts, it is aimed at improving the stability and activity of Bi-based visible light driven photocatalysts photocatalysts by combination of graphitic carbon nitride (g-C3N4). G-C3N4/Bismuth-based photocatalytic materials with high activity and stability were prepared by hydrothermal or solvent-thermal method. The effects of content on the photocatalytic activity of g-C3N4/Bismuth-based composite photocatalysts will be investigated by photodecomposition of organic pollution. The separation and transfer of photogenerated charge carriers will be investigated, the interaction mechanism between g-C3N4 and Bismuth-based Photocatalytic materials and the factors enhancing the visible-light activity will be discussed. The factors and rules influencing the Bismuth-based photocatalysts activity decline will be explored, and the potential mechanism of improving stability of Bi-based photocatalytic materials by g-C3N4 will be discussed. A recyclable procedure with the Bismuth-based photocatalysts to degrade organic pollutants will be worked out. The implementation of this project will pave the way for the practical applications of bismuth-based photocatalysts in the water pollution, and laying a theoretical foundation for design and fabrication of new visible-light-driven photocatalysts with high photoactivity and stability.

铋基光催化材料具有良好的可见光活性，在利用太阳能去除水中有机物上具有广阔的应用前景，然而铋基光催化材料在光催化反应过程中易被光腐蚀，严重制约了其实际应用。本项目在研究各种铋基光催化材料光腐蚀的基础上，拟通过复合石墨相氮化碳（g-C3N4）以提高其稳定性和活性。通过水热或溶剂热法制备高活性和高稳定性的g-C3N4/铋基复合光催化材料，在可见光下降解有机污染物，研究g-C3N4/铋基光催化材料组分与光催化活性之间的内在联系。分析研究光生载流子的分离和转移规律，揭示g-C3N4与铋基光催化材料的相互作用机制和增强可见光活性的因素。探究影响常见铋基光催化材料活性下降的因素及规律，阐明g-C3N4提高铋基光催化材料稳定性的机理，探索铋基复合光催化材料循环稳定地降解有机污染物的工艺，为铋基光催化材料在水污染治理的实际应用上提供实验依据，也为设计制备高活性和高稳定性的新型可见光光催化材料奠定理论基础。

有机污染物会严重威胁人类健康，并严重破坏生态系统。光催化氧化技术能直接利用太阳能完全降解有机污染物，开发高效稳定的可见光光催化剂是处理工业废水有机污染物的有效途径之一，具有重要的理论和应用价值。铋基光催化材料具有良好可见光吸收性能，本项目拟通过复合石墨相氮化碳（g-C3N4）以提高其稳定性和活性。目前通过水热或微波辅助法制备了Bi2S3/BiOCl/g-C3N4 纳米片、Fe(III)/Bi2O2CO3微米花、Ag@AgBr/Bi2WO6花状复合物、夹心形BiVO4纳米片和Fe掺杂Bi2O2CO3纳米片，在可见光下降解有机污染物具有良好的活性和稳定性。分析研究这些材料中光生载流子的分离和转移规律，揭示复合铋基光催化材料的相互作用机制和增强可见光活性的因素。同时合成了石墨相氮化碳（g-C3N4）纳米片或量子点，制备了几种石墨相氮化碳（g- C3N4）复合传感器，用于电催化检测生物小分子。