Enhanced adsorption and photodegradation of phenol in aqueous suspensions of titania/graphene oxide composite catalysts

Abstract

This study uses a hydrothermal method to synthesize titania@graphene oxide (TGO) composite catalysts for the photodegradation of phenol under UV illumination in liquid phase. The graphene oxide (GO) sheets were derived from natural graphite powders using a modified Hummers’ method. One efficient hydrothermal method reinforces the adhesion between GO sheets and titania nanoparticles (T), forming composite catalysts. The adsorption capacities of phenol on T, GO, and TGO composites were experimentally determined, and the order of adsorption efficiency was found to be TGO > GO > T. The photocatalytic performance on the composite catalysts was systematically evaluated by the pseudo first-order kinetic model. Experimental results reveal that the TGO composite exhibits the best photocatalytic activity, including apparent rate constant and equilibrium catalytic ability, among the tested samples. This enhanced performance may be attributed to the well-dispersed titania nanocatalysts that are attached to the GO sheets, which offer homogeneous active sites for phenol adsorption, followed by photodegradation. Accordingly, the robust design of TGO composite catalysts offers an effective route for the treatment of organic wastewater.