Enhancement of visible-light photocatalytic activity of Cu3B2O6 hybridized with g-C3N4

Abstract

Novel g-C3N4/Cu3B2O6 hybrid photocatalysts were successfully synthesized by a liquid chemisorption and thermal post-treatment method. The as-synthesized samples were extensively characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared (FTIR), X-ray photoelectron spectra (XPS), field-emission scanning electron microscopy (FE-SEM), transmission electron microscope (TEM), UV–vis diffuse reflectance spectra (UV-vis DRS), Brunauer-Emmett-Teller (BET), photoluminescence (PL) and photocurrent. The photocatalytic performances of the g-C3N4/Cu3B2O6 composites were evaluated by degrading methylene blue (MB) using H2O2 as an oxidant under visible-light irradiation. It was found that 60% g-C3N4/Cu3B2O6 sample exhibited optimal kinetic constant of 0.0474min−1, which was 3.16 and 2.14 times higher than that of g-C3N4 and Cu3B2O6, respectively. This enhancement was mainly attributed to the elevated separation efficiency of photogenerated electron-hole pairs with the integration g-C3N4 and Cu3B2O6, resulting in the enhanced activity of activating H2O2 to decolorize MB under visible-light. The radical trapping experiments demonstrated that h+, e− and ·OH were responsible for MB photodegradation. Furthermore, an underlying mechanism of the g-C3N4/Cu3B2O6+H2O2+vis photocatalytic system was proposed.