One-step calcination method for synthesis of mesoporous g-C3N4/NiTiO3 heterostructure photocatalyst with improved visible light photoactivity

A novel g-C3N4/NiTiO3 composite was fabricated by one-step calcination method using dicyandiamide, tetrabutyl titanate and nickel acetate as the precursors. The samples were characterized by scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, N-2 adsorption/desorption isotherms, UV-vis diffuse reflection spectroscopy and photoluminescence spectroscopy. It was indicated that the hybrids owned a large surface area, mesoporous structure and improved visible light absorption. The optimal g-C3N4 content in the g-C3N4/NiTiO3 composite was 18.4 wt%, and the corresponding visible-light removal rate for nitrobenzene was 0.0132 min(-1), about 1.6 times higher than that of pure NiTiO3. The enhanced photocatalytic activity may be attributed to the large surface area, stronger absorption in the visible region and efficient electron-hole separation.