LAUSR

Abstract Novel g-C 3 N 4 /Cu 3 B 2 O 6 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-C 3 N 4 /Cu 3 B 2 O 6 composites were evaluated by degrading methylene blue (MB) using H 2 O 2 as an oxidant under visible-light irradiation. It was found that 60% g-C 3 N 4 /Cu 3 B 2 O 6 sample exhibited optimal kinetic constant of 0.0474 min −1 , which was 3.16 and 2.14 times higher than that of g-C 3 N 4 and Cu 3 B 2 O 6 , respectively. This enhancement was mainly attributed to the elevated separation efficiency of photogenerated electron-hole pairs with the integration g-C 3 N 4 and Cu 3 B 2 O 6 , resulting in the enhanced activity of activating H 2 O 2 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-C 3 N 4 /Cu 3 B 2 O 6  + H 2 O 2  + vis photocatalytic system was proposed.