Abstract:

The WO₃/BiOCl_0.7I_0.3 composite photocatalytic materials were prepared by simple calcination method and in-situ precipitation method. The microstructure and chemical composition of the synthesized materials were characterized by XRD, SEM, XPS and UV-Vis DRS. The photocatalytic performance of the WO₃/BiOCl_0.7I_0.3 composite was evaluated by the visible light catalytic degradation of 20mg/L tetracycline hydrochloride. The results showed that the WO₃/BiOCl_0.7I_0.3 composite had better photocatalytic performance than the single BiOCl_0.7I_0.3 and WO₃. When the molar ratio of W to Bi was 1∶15, the composite had the highest photodegradation rate, reaching the maximum value of 93.84% at 60 min under visible light and still had good photocatalytic activity after four cycles of test. The results of free radical capture test and electron spin resonance spectroscopy were analyzed. It was found that h⁺ and •O₂^- were identified as the main active substances in photocatalysis. The photocatalytic mechanism of Z-type heterostructure of WO₃/BiOCl_0.7I_0.3 composite was proposed. The research provided a new idea for the development of new visible light photocatalytic materials and a new way for the treatment of antibiotic wastewater.

Key words: composites, catalysis, WO₃/BiOCl_0.7I_0.3, visible light, photodegradation

摘要：

通过简单的煅烧法和原位沉淀法制备了WO₃/BiOCl_0.7I_0.3复合光催化材料，利用X射线衍射（XRD）、扫描电子显微镜（SEM）、X射线能谱（XPS）、紫外可见漫反射光谱（UV-Vis DRS）等表征手段对合成材料的微观形貌、化学组成等进行表征。并通过可见光催化降解20mg/L盐酸四环素来评价材料的光催化性能，结果显示，WO₃/BiOCl_0.7I_0.3复合材料较单一的BiOCl_0.7I_0.3和WO₃具有更优的光催化性能，其中W与Bi摩尔比为1∶15时，复合材料具有最高的光降解率，可见光下60min达到最高值93.84%，且四次循环试验后仍具有较好的光催化活性。对自由基捕获试验结果及电子自旋共振光谱进行分析，明确了h⁺和•O₂^-为光催化主要活性物质，提出WO₃/BiOCl_0.7I_0.3复合材料Z型异质结构的光催化作用机理。研究为新型可见光光催化材料的开发提供了新思路，为抗生素类废水的处理提供了新途径。

关键词: 复合材料, 催化, WO₃/BiOCl_0.7I_0.3, 可见光, 光降解