Study on the mechanism of inactivation of marine microorganisms by IrO2/ZnWO4 composite photocatalyst

In this paper, ZnWO4 photocatalysts were prepared by hydrothermal method, after which IrO2 was loaded on ZnWO4 by photodeposition to synthesize IrO2/ZnWO4 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 IrO2 modification to enhance the sterilization of ZnWO4 was as follows: first, IrO2 modification significantly enhanced the effective chlorine yield of the samples. Second, IrO2 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.