Synthesis of ZnO/rGO/TiO2 Composite and Its Photocatalytic Activity for Rhodamine B Degradation

Abstract

Nowadays the growth of the textile industry in Indonesia is increasing. An example of dangerous textile waste is Rhodamine-B. Therefore, a method to treat Rhodamine B waste is needed. One method that can be used is photocatalysis. ZnO and TiO2 semiconductors are known as good photocatalyst material because they have a small band gap energy. In addition, reduced graphene oxide (rGO) has a potential due to its good conductivity and large surface area. This study aims to synthesize ZnO/rGO/TiO2 composite. Analysis of the composite shows peaks correspond to diffraction pattern of ZnO, TiO2, and rGO. Based on scanning electron microscope analysis, the surface morphology of the composite was in the form of sheets (rGO), agglomerates (TiO2), and hexagonal nanorod (ZnO). Further confirmation by EDX analysis shows elemental compositions of Zn, Ti, O, C (18.44, 7.44, 46.01, 28.11, respectively). FTIR analysis resulting in bands of C-O at 998 cm−1, Ti-O-Ti at 506 cm−1, and Zn-O at 497 cm−1. Photocatalysis test using the composite gave the optimum value of Rhodamine-B degradation of 94.72 % under UV light irradiation for 5 hours.