N-doped rutile TiO2 composite g-C3N4 with Z-Scheme boosts photocatalytic hydrogen production under visible light

Abstract The photocatalysis technology is one of the recent research hotspots to solve a series of social problems such as energy crisis and environmental pollution. It is an important way to improve the photocatalytic efficiency by constructing heterojunction and improving the utilization rate of sunlight. In this paper, N-doping rutile TiO 2 (N-rTiO 2 ) and graphite phase carbon nitride (g-C 3 N 4 ), as cheap, stable and non-toxic catalysts, were successfully composited. Although N-rTiO 2 could not meet the hydrogen production condition, after formed a Z-scheme heterojunction with g-C 3 N 4 , which improved the photocatalytic hydrogen production performance by 2.57 times compared with pristine g-C 3 N 4 . Moreover, a DFT calculation has analyzed the band structure, density of state, work function, differential charge density and Bader charge distribution of samples to reveal the photocatalytic mechanism. It is further proved that the formation of Z-scheme effectively promotes the improvement of photocatalytic performance. This study provides a feasible idea for designing and expanding new and cheap photocatalysts in the renewable energy fields. This study efficient hybrid catalysts for other applications in the renewable energy fields.