氯氧化铋的形貌调控及其光催化降解全氟辛酸

Morphological Regulation of Bis-muth Oxychloride and Its Photocatalytic Degradation of Perfluorooctanoic Acid

为了探究形貌对氯氧化铋(BiOCl)光催化去除全氟辛酸(PFOA)性能的影响,通过改变溶剂热法合成体系的溶剂种类制备得到不同形貌的BiOCl。其中,二维纳米片BiOCl具有最优异的光催化去除PFOA性能,即模拟太阳光辐射一小时对PFOA的降解率为98.8%。电子顺磁共振(EPR)、漫反射光谱(DRS)、瞬态光电流响应测试(IT)和光致发光(PL)测试结果表明,具有更大的比表面积、更多的氧空位、更窄的带隙以及更高的载流子分离效率的样品并未表现出更优异的光催化性能。电化学阻抗谱(EIS)测试结果表明,不同形貌样品的载流子迁移速率顺序与其光催化去除PFOA的活性顺序一致,表明载流子迁移速率可能是影响其光催化活性的重要因素。

In order to explore the effect of morphology on the photocatalytic removal of perfluorooctanoic acid (PFOA) by bismuth oxychloride (BiOCl), BiOCl with different morphologies were prepared by changing the solvent type of solvothermal synthesis system. Among them, two-dimensional nanosheets BiOCl exhibited the best photocatalytic removal performance for PFOA, with a degradation rate of 98.8% on PFOA after simulating solar radiation for one hour. The results of electron paramagnetic resonance (EPR), diffuse reflectance spectrosco-py (DRS), transient photocurrent response (IT), and photoluminescence (PL) tests indicated that samples with larger specific surface area, more oxygen vacancies, narrower bandgap, and higher carrier separation efficiency do not exhibit better photocatalytic performance. The electrochemical impedance spectroscopy (EIS) test results indicated that the carrier migration rate order of sam-ples with different morphologies was consistent with their photocatalytic activity order for remov-ing PFOA, indicating that the carrier migration rate may be an important factor affecting their pho-tocatalytic activity.