Photocatalytic Degradation of Phenol and Methyl Orange with Titania-Based Photocatalysts Synthesized by Various Methods in Comparison with ZnO–Graphene Oxide Composite

Abstract

Photocatalysis is one of the effective methods to treat wastewater and degrade pollutants. Titania (TiO2) is usually chosen based on its superior properties and its high performance as reported in many publications. However, the properties of TiO2 may be influenced by the synthesis method. In this work, several methods were applied to synthesize TiO2, and its modified form (composite with graphene oxide) to explore the influence of synthesis method on its photocatalytic activity for the methyl orange and phenol degradation under UV light illumination. The results showed that the synthesis method significantly influences on the morphology, particle sizes and surface area of the catalysts as examined by SEM and BET techniques but did not differentiate crystal structure and crystallite dimensions of catalysts as seen by XRD measurement. TiO2 catalyst synthesized by hydrothermal method using P123 template was almost anatase phase, possessed high surface area (110 m2/g) and exhibited highest activity for methyl orange and phenol degradation under UV light illumination. However, the addition of graphene oxide to the catalyst is not yet able to improve its activity under visible light. Compared with ZnO-graphene oxide photocatalyst (almost 100% phenol degraded after 275 min of the treatment), TiO2-graphene oxide catalyst exhibited much less activity for methyl orange and phenol degradation under visible light irradiation.