Abstract:

The Z-scheme CuBi₂O₄/BiOBr (CBOB) heterojunction was prepared by a solvothermal method and compounded with graphene hydrogel (GH) to obtain CuBi₂O₄/BiOBr@GH (CBOBG). The crystal structure, surface composition, microstructure, specific surface area and photoelectric properties of the photocatalyst were characterized by XRD, XPS, SEM, TEM, N₂ adsorption-desorption, UV-vis DRS, PL spectra and electrochemistry. The photocatalytic activity of CBOBG was further studied by the tetracycline degradation coupled reduction of Cr(‍Ⅵ) under visible light. The results showed that the degradation rate of tetracycline and the reduction rate of Cr(‍Ⅵ) of CBOBG reached 86.1% and 100% respectively within 120min. The main active substances in the degradation process were superoxide radical and hole, while those in the reduction process were electron.

Key words: composites, CuBi₂O₄/BiOBr, graphene hydrogel, catalyst, photocatalysis

摘要：

采用溶剂热法制备Z型CuBi₂O₄/BiOBr（CBOB）异质结，并与石墨烯水凝胶（GH）复合得到CuBi₂O₄/BiOBr@GH（CBOBG）。通过X射线衍射、X射线光电子能谱、扫描电子显微镜、透射电子显微镜、N₂吸附-脱附、紫外-可见光谱、荧光光谱和电化学等表征方法对催化剂的晶体结构、表面组成、微观形貌、比表面积与光电性能进行分析。在可见光下，通过降解四环素耦合还原Cr(Ⅵ)实验，考察了CBOBG的光催化活性。实验结果表明，CBOBG在120min内，对四环素的降解率达到了86.1%，对Cr(Ⅵ)的还原率达到了100%。通过活性物种捕获实验证明，降解过程的主要活性物质为超氧自由基和光生空穴，还原过程的主要活性物质为光生电子。

关键词: 复合材料, CuBi₂O₄/BiOBr, 石墨烯水凝胶, 催化剂, 光催化