Disinfection effects induced by graphene-based photocatalytic composites under solar light illumination

Abstract

ZnO/graphene and ZnO/stellerite composite photocatalysts were prepared through a facile hydrothermal-calcination processing with zinc acetate,urea,natural stellerite and graphene.The composition,morphology,specific surface area,pore size distribution and light absorption properties of prepared composites were characterized by scanning electron microscopy (SEM),X-ray diffraction (XRD),nitrogen adsorption/desorption and UV-visible diffused reflectance spectroscopy (UV-vis DRS).It was found that the prepared photocatalysts ZnO/stellerite and ZnO/graphene had wurtzite ZnO phase morphology with ZnO paticle sizes of 22.42 nm and 15.72 nm.SBET of composites were 16.54 m2/g and 35.55 m2/g respectively.3D structure between ZnO and graphene resulted in the response to visible light region,reduced recombination of free charges,and enhanced interface charge transfer.The disinfection action towards Staphylococcus aureus (S.aureus) under solar light showed that the optimal amount of ZnO/graphene was 100 mg/L.ZnO/graphene exhibited significantly enhanced photocatalytic disinfection efficiency than ZnO/stellerite powders,and disinfection rate up to 1.17 h-1 is 1.31 times that of ZnO/stellerite composite.

Keywords

• zno
• graphene
• stellerite
• <i>s</i>.<i>aureus</i>
• disinfection rate