Effect of mass ratio on rGO/TiO2 composite as catalyst for methylene blue degradation under UV irradiation

Abstract

Adsorption and photocatalytic are commonly used methods for the removal of dye contained in industrial wastewater. Therefore, this study aimed to combine reduced Graphene Oxide (rGO) with Titanium Oxide (TiO2) through various compositions using the hydrothermal method to obtain a catalyst of rGO/TiO2 nanocomposites for the removal of contaminants from wastewater. The synthesized rGO/TiO2 nanocomposites were mixed with methylene blue (MB) to reduce their content in water under dark conditions and UV light irradiation. The change of the optical properties of MB under both conditions was also examined, where a decrease in absorbance was observed. Under UV light irradiation, the maximum wavelength [Formula: see text] of MB shifted from 664[Formula: see text]nm to 649[Formula: see text]nm but remained constant at 664[Formula: see text]nm in dark conditions. The results of optical characterizations confirmed that the adsorption of MB by rGO/TiO2 nanocomposites under dark conditions did not change the MB structure. However, a significant degradation was observed with photocatalytic process under UV light irradiation. Nanocomposites rGO/TiO2 with rGO 60% and TiO2 40% (GT40) have better performance in reducing MB under UV light irradiation.