石墨相C3N4-铋系半导体S-scheme异质结的设计、制备及其光催化甲烷氧化制甲醇研究

针对目前已报道的甲烷氧化光催化剂对可见光响应不足、光生载流子易复合、产物选择性低等突出问题，结合S-scheme异质结半导体具有优异的光生载流子分离效率和氧化还原能力等优点，本项目以研制可见光驱动甲烷选择性氧化制备甲醇的高效S-scheme催化剂为研究目标。主要研究内容为：（1）基于g-C3N4和Bi2WO6、BiOBr半导体能带位置和功函的差异，采用静电自组装、原位生长的合成策略制备一系列g-C3N4-铋系半导体S-scheme异质结高效光催化剂；（2）分析催化剂组成、结构、光电性质，尤其光生载流子的分离、迁移及复合情况；（3）考察催化剂对甲烷氧化制甲醇的催化性能，阐明催化剂结构-性质-性能的关系，明晰催化作用机制。通过本项目的实施，希望为新型、高效光催化甲烷氧化催化剂的开发提供重要的参考依据。

Most of the reported photocatalysts for methane oxidation have shortcomings, such as insufficient response to visible light, easy recombination of photogenerated charge carriers and low products selectivity. S-scheme heterojunction photocatalysts have attracted much attention in recent years owing to their excellent photogenerated charge carriers separation efficiency and redox ability. This project aims to develop high-efficiency S-scheme photocatalysts for visible-light-driven selective oxidation of methane to methanol. The main research contents are as follows: (1) Design and preparation of a series of g-C3N4-bismuth based semiconductor S-scheme heterojunction photocatalysts based on the difference of band positions and work functions between g-C3N4 and bismuth based semiconductors (Bi2WO6, BiOBr) by means of electrostatic self-assembly and in-situ growth. (2) Characterization of the composition, structure and photoelectric properties of the catalysts, especially the separation, migration and recombination of photogenerated charge carriers. (3) Investigation of the photocatalytic performance of the as-synthesized materials in oxidation of methane to methanol, and clarification of the relationship between the structure, properties and performance of the catalysts. This project is expected to provide important information for the development of new and efficient photocatalytic methane oxidation catalysts.