Enhanced photocatalytic activity of TiO2 by reduced graphene oxide in mineralization of Rhodamine B dye

A series of reduced graphene oxide (RGO)-TiO2 nanocomposites with varying weight percentage of RGO were prepared by solvothermal method. The as-prepared samples were characterized by FT-IR, XRD, TEM, UV-Visible DRS, PL, EIS and Raman analysis. The photocatalytic activity was evaluated toward the decolourization/degradation of Rhodamine B dye (RhB) under UV light. The effects of various parameters such as RGO content, initial dye concentration, pH and catalytic dose on decolourization were studied and optimized. The results were also compared with bare TiO2. At optimized conditions the influence of various dye bath additives on decolourization has been examined and discussed in detail. It was found that the RGO-TiO2 composites (RGOT) had a better photocatalytic activity than TiO2. The enhanced activity is due to the presence of bi-dimensional RGO network in the composite photocatalysts which suppresses the recombination of photo-induced charge carriers. Reusability test results revealed that the catalyst is photostable, easily separable and reusable. The degradation kinetics obeys LangmuirHinshelwood model. (C) 2015 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.