EDTA辅助水热法合成BiYO3及其高效光还原CO2性能研究

新型光催化剂的研制是光驱动下CO₂转化为高附加值化学品或燃料的核心问题,对实现“碳达峰·碳中和”目标具有重要意义。本文通过乙二胺四乙酸(EDTA)辅助水热法合成一系列新型Bi-Y-O光催化剂体系,发现样品的晶体结构随EDTA的添加量不同而发生变化。添加0.4 g EDTA或未添加EDTA时均可得到BiYO₃晶体,而添加0.8 g和1.2 g EDTA时分别制得Bi_1.46Y_0.54O₃和Bi₃YO₆晶体。光催化CO₂还原性能测试结果表明,添加0.4 g EDTA制备的BiYO₃具有最佳光催化CO₂还原活性,其CO产率为18.29 μmol·g^-1·h^-1,且3次循环使用后CO产率仍达17.32 μmol·g^-1·h^-1,明显高于其他样品。结合表征结果分析可知:EDTA的引入不仅可调控BiYO₃的结构形貌,而且拓宽其光响应范围、提高光生电子-空穴的分离效率,从而增强光催化还原CO₂性能,为新型高效B-Y-O光催化体系的研究提供基础科学数据。

EDTA-Assisted Hydrothermal Synthesis of BiYO3 with High-Efficient Photoreduction CO2 Performance

The research development of novel photocatalysts is the core issue of photo-driven CO₂ conversion into high value-added chemicals or fuels, which should be of important significance for achieving the goal of “carbon peak and carbon neutralization”. In this paper, a series of novel Bi-Y-O photocatalyst systems were synthesized by EDTA-assisted hydrothermal method, and with the change of EDTA amount, the crystal structures of as-prepared samples are variational. BiYO₃ crystal is obtained with 0.4 g EDTA addition or without EDTA, while Bi_1.46Y_0.54O₃ and Bi₃YO₆ crystals are synthesized with 0.8 g and 1.2 g EDTA addition, respectively. The photocatalytic CO₂ reduction tests reveal that as-prepared BiYO₃ with 0.4 g EDTA addition exhibits the best CO₂ photoreduction activity, and CO yield is 18.29 μmol·g^-1·h^-1. After three cycle tests, CO yield still reaches 17.32 μmol·g^-1·h^-1, higher obviously than CO yields of other samples. Finally, the characterization analysis results show that the assistance of EDTA could not only regulate the structure morphology of BiYO₃, but also broaden the light response and enhance the separation efficiency of photogenerated electron-hole pairs, and consequently improve the photocatalytic CO₂ reduction performance. The research in this paper provides basic scientific data for the investigation on novel highly-effective B-Y-O photocatalytic system.