A simple large-scale method for preparation of g-C₃N₄/SnO₂ nanocomposite as visible-light-driven photocatalyst for degradation of an organic pollutant

In this work, we report a simple large-scale method for preparation of g-C₃N₄/SnO₂ nanocomposite as visiblelight-driven photocatalyst. The nanocomposite was prepared by a facile refluxing method at 96 °C for one hour using g-C₃N₄, SnCl₄, and NaOH as the starting materials. The prepared samples were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, energy dispersive analysis of X-rays, X-ray photoelectron spectroscopy, diffuse reflectance spectroscopy, Fourier transform-infrared spectroscopy, and photoluminescence (PL) techniques. Photocatalytic activity of the samples was investigated by degradation of rhodamine B (RhB) under visible-light irradiation. The degradation rate constant of RhB on g-C₃N₄ (90%)/SnO₂ nanocomposite is about 2.1 and 9.3-fold higher than those of g-C₃N₄ and SnO₂, respectively. Increase of the photocatalytic activity was related to the separation of electron–hole pairs, confirmed by PL technique. Moreover, the degradation rate constant was initially increased with refluxing time up to one hour and then decreased. It was found that superoxide ions and holes are the main reactive species in the degradation reaction. This work can be applied for preparation of other visible-light-driven photocatalysts based on g-C₃N₄.