Study on the mechanism of inactivation of marine microorganisms by IrO 2 /ZnWO 4 composite photocatalyst

In this paper, ZnWO 4 photocatalysts were prepared by hydrothermal method, after which IrO 2 was loaded on ZnWO 4 by photodeposition to synthesize IrO 2 /ZnWO 4 composite photocatalysts. The prepared photocatalysts were characterized by XRD, SEM, TEM, XPS, and UV–Vis diffuse reflectance spectroscopy (DRS). The photocatalytic activity was investigated by inactivating bacteria in natural seawater. The effect of varying the deposition amount of IrO 2 on the photocatalytic activity was investigated. The mechanism of IrO 2 modification to enhance the sterilization of ZnWO 4 was as follows: first, IrO 2 modification significantly enhanced the effective chlorine yield of the samples. Second, IrO 2 modification also promoted the charge separation efficiency of the samples. The present work confirms that photocatalytic production of effective chlorine is an important active species for sterilization in seawater systems, which provides a new idea for photocatalytic purification technology in seawater medium.