Abstract: Tetracycline hydrochloride (TC), as a broad-spectrum antibiotic, is widely used in clinical medicine, animal husbandry, and aquaculture. It makes a large amount of TC wastewater discharged into the aquatic environment and ultimately endangers human health through the food chain. As an advanced oxidation technology, photocatalysis has significant advantages in refractory wastewater treatment. In this study, Bi2WO6 was prepared by the hydrothermal method, and the composite CeO2/Bi2WO6 was synthesized by doping appropriate CeO2 in Bi2WO6. The crystal structure, morphological characteristics, and light absorption performance were characterized. The results showed that the CeO2/Bi2WO6 ratio, catalyst dosage, initial concentration of TC, and initial pH value of the solution had a significant impact on the catalytic degradation of TC by photocatalysis under visible light. The formation of CeO2/Bi2WO6 heterojunction could effectively improve the separation efficiency of photogenerated electron-hole pairs, thereby greatly enhancing photoactivity. When the molar ratio of CeO2/Bi2WO6 was 1:3, the initial pH value was 5, the initial concentration of TC was 8 mg/L, and the dosage of CeO2/Bi2WO6 was 0.4 g/L, the removal rate of TC and TOC of the solution could reach up 90.7% and 64.3%, respectively. The possible photocatalytic degradation mechanism of TC over CeO2/Bi2WO6 was proposed according to the results of the free radical captured experiment and the potential value of the conduction band and valence band of the catalyst. After six cycle experiments, the removal rate of TC by CeO2/Bi2WO6 catalyst could still reach 86.4%.

Key words: CeO2/Bi2WO6, Z-scheme heterojunction, visible light, photocatalysi, tetracycline hydrochloride

摘要： 盐酸四环素(TC)作为一种广谱抗生素，广泛应用于临床医学、畜牧业和水产养殖业，致使大量TC废水排放到水生环境中，并通过食物链危害人类健康。光催化作为一种先进的氧化技术，在处理难降解废水方面具有显著优势。本工作在水热法制备Bi2WO6的基础上，以共沉淀法掺杂适量的CeO2合成复合催化剂CeO2/Bi2WO6，并对其晶体结构、形貌特征和光吸收性能等进行表征。结果表明，CeO2/Bi2WO6摩尔比、催化剂投加量、TC初始浓度和溶液初始pH值对可见光催化降解TC有显著的影响，其中，CeO2/Bi2WO6异质结的形成能够有效提高光生电子空穴的分离效率，进而增强光催化效率。当CeO2/Bi2WO6的摩尔比为1:3、溶液初始pH为5、TC浓度为8 mg/L、CeO2/Bi2WO6投加量为0.4 g/L时，TC和溶液总有机碳(TOC)的去除率可分别达90.7%和64.3%。根据自由基捕获实验和催化剂的价带、导带位置，提出CeO2/Bi2WO6异质结光催化降解TC的机理。经过6次循环实验，CeO2/Bi2WO6催化剂对TC去除率仍为86.4%。

关键词: CeO2/Bi2WO6, Z型异质结, 可见光, 光催化, 盐酸四环素