Enhanced photocatalytic degradation of malachite green by sulfur-doped titanium dioxide/porous reduced graphene oxide

Abstract

In this study, the sulfur-doped titanium dioxide (S-TiO2) was prepared via the sol-gel method, while the effect of calcination temperature was also investigated. The sulfur-doped titanium dioxide/porous reduced graphene oxide (S-TiO2/rGO) was successfully synthesized via the in-situ method with the support of hydrothermal and ultrasonication processes. The characterization of the materials was also scrutinized via several advanced analysis methods, including X-ray diffraction (XRD), Raman, scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and photoluminescence (PL). In terms of the photodegradation performance, the malachite green (MG) removal efficiency of the S-TiO2/rGO (99.86 %) was higher than that of S-TiO2 (78.88 %). Besides, the chemical oxygen demand (COD) was analyzed to investigate the mineralization of MG in the photodegradation reaction. Concurrently, the removal efficiency of MG was also determined under the illumination of UV light and sunlight. The material shows high reusability after ten consecutive runs. According to the results, the S-TiO2/rGO material exhibits excellent potential in the degradation of organic pollutants in the water reservoirs.