In situ growth of TiO2 nanocrystals on g-C3N4 for enhanced photocatalytic performance

Abstract

Well dispersed TiO₂ nanocrystals with (001) facets were successfully grown in situ on g-C₃N₄ through a facial solvothermal method. The resultant TiO₂/g-C₃N₄ composites exhibit remarkably higher efficiency for photocatalytic degradation of phenol as compared to pure catalysts (g-C₃N₄ or TiO₂) or mechanically mixed TiO₂/g-C₃N₄. The optimal composite with 11.2 wt% TiO₂ showed the highest degradation rate constant, which is 2.8 times that of pure g-C₃N₄, 2.2 times that of pure TiO₂, and 1.4 times that of mechanically mixed TiO₂/g-C₃N₄. The enhanced photocatalytic activity is mainly attributed to the effective charge separation derived from two aspects: (1) well matched energy levels between TiO₂ and g-C₃N₄ and (2) a uniform and close contact between TiO₂ and g-C₃N₄ that resulted from the in situ growth of highly dispersed TiO₂ nanocrystals. The TiO₂/g-C₃N₄ hybrid material prepared in this study is expected to provide a good foundation for the further design and synthesis of advanced TiO₂/g-C₃N₄-based functional materials, and the in situ growth method developed is hopeful to provide a new strategy for the synthesis of other semiconductor-modified g-C₃N₄ materials.