Preparation of g-C3N4/TiO2 by template method and its photocatalytic performance

A method for preparing TiO2 supported on g-C3N4 by freeze-drying was proposed using NaCl as template as well as TiO2 dispersion and melamine as raw materials. This method solves the problems of low specific surface area and fast electron-hole recombination rate of traditional g-C3N4. During the calcination process, the generated g-C3N4 and TiO2 formed a heterojunction, which reduced the rate of electron-hole combination. After removing the template, a 3D porous g-C3N4 network supporting TiO2 was obtained. In this study, XRD, FT-IR, TG-DSC, XPS, TEM and SEM were used to explore the microstructure evolution of g-C3N4/ TiO2 at different stages. And then the band structures of different samples were analyzed by UV-Vis. Finally, the photocatalytic activity of different samples was studied by photolytic water experiment. The results showed that the TiO2 nanoparticles were successfully supported on the surface of the 3D porous g-C3N4 network, and the photocatalytic activity of g-C3N4 was significantly improved. When g-C3N4: TiO2 = 2.5: 1, the sample had the highest photocatalytic efficiency, and the hydrogen production rate reached 200.806 μmol/g/h.