Photocatalytic hydrogen under visible light by nitrogen-doped rutile titania graphitic carbon nitride composites: an experimental and theoretical study

Photocatalysis technology is one of the hotspots in recent years 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, nitrogen-doped rutile titania and graphite phase carbon nitride composites were synthesized successfully. Although nitrogen-doped rutile titanium dioxide cannot meet the thermodynamic conditions of hydrogen production, the photocatalytic hydrogen production rate of nitrogen-doped rutile titania/graphitic carbon nitride composite reaches to 2121.9 μmol h−1 g−1, which is 2.57 times higher than that of the pristine graphitic carbon nitride. By means of density functional theory, the band structure, state density, work function, differential charge density, and Bader charge distribution of the samples were analyzed. It was revealed that the Z-scheme heterojunction formed at the carbon nitride interface of nitrogen-doped rutile titanium dioxide/graphite carbon nitride effectively promoted the improvement of photocatalytic performance. This study provides a feasible idea for the design and popularization of new cheap photocatalysts in the field of renewable energy.