Enhanced performance of g-C₃N₄/TiO₂ photocatalysts for degradation of organic pollutants under visible light

Photocatalytic degradation is one of the most promising remediation technologies in terms of advanced oxidation processes (AOPs) for water treatment. In this study, novel graphitic carbon nitride/titanium dioxide (g-C₃N₄/TiO₂) composites were synthesized by a facile sonication method. The physicochemical properties of the photocatalyst with different mass ratios of g-C₃N₄ to TiO₂ were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), N₂ sorption, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and UV-vis DRS. The photocatalytic performances were evaluated by degradation of methylene blue. It was found that g-C₃N₄/TiO₂ with a mass ratio of 1.5:1 exhibited the best degradation performance. Under UV, the degradation rate of g-C₃N₄/TiO₂ was 6.92 and 2.65 times higher than g-C₃N₄ and TiO₂, respectively. While under visible light, the enhancement factors became 9.27 (to g-C₃N₄) and 7.03 (to TiO₂). The improved photocatalytic activity was ascribed to the interfacial charge transfer between g-C₃N₄ and TiO₂. This work suggests that hybridization can produce promising solar materials for environmental remediation.