摘要
Designing simple, efficient, and environmentally friendly methods to construct high-efficient photocatalysts is an important strategy to promote the further development of the field of photocatalysis. Herein, flower-like carbon quantum dots(CQDs)/Bi OBr composite photocatalysts have been prepared via in-situ synthesis by mechanical ball milling in the existence of ionic liquid. The CQDs/Bi OBr composites exhibit higher photo-degradation performance for tetracycline(TC) than Bi OBr monomer and the commercial Bi_(2)O_(3) under visible light irradiation. For comparison, the different Br sources and synthetic methods are chosen to prepare Bi OBr and CQDs/Bi OBr composites. Photocatalysts prepared by ball milling and ionic liquid present significantly enhanced photocatalytic performance for removing TC. In addition, the introduction of CQDs could distinctly enhance the photocatalytic performances of pure Bi OBr. The reason is that CQDs as electron acceptor effectively separate electrons and holes and inhibit their recombination. The intermediates during photocatalytic degradation were tested using liquid chromatography-mass spectrometry(LC-MS) and possible degradation pathways were given. During degradation, ·OH, O_(2)^(·-)and h^(+) were identified to be the main active species based on electron spin resonance(ESR) spectra and free radical trapping experiments. A possible mechanism of CQDs/Bi OBr with enhanced photocatalytic performances was further proposed.
基金
financially supported by the National Natural Science Foundation of China (Nos. 22108106, 22108108, 22109055, 21878134)
Natural Science Foundation of Jiangsu Province (BK20210742)
China Postdoctoral Science Foundation (No. 2020M680065)
Hong Kong Scholar Program (No. XJ2021021)
Key Laboratory of Electrochemical Energy Storage and Energy Conversion of Hainan Province (No. KFKT2021005)。
作者简介
Corresponding authors:Pengjun Liu.Emails:Liupj12@126.com;Corresponding authors:Jiexiang Xia.Emails:xjx@ujs.edu.cn。
