Construction of novel SrHNbO·HO/g-CN heterojunction with enhanced visible light photocatalytic activity for hydrogen evolution.

Construction of heterojunction is an effective strategy to conquer the severe charge carrier recombination limitation of single component g-CN photocatalyst. In the present work, novel heterojunctions composed of g-CN nanosheets and SrHNbO·HO nanooctahedrons were constructed via a simple hydrothermal method. The as-prepared SrHNbO·HO/g-CN (HSN/CN) heterojunction showed high photocatalytic activity in the water splitting reactions. Specially, it is found that the developed 20 wt%-HSN/CN heterojunction shows high water splitting activity with H evolution rate up to 469.4 μmol g, which was much higher than that of bare CN. This enhanced photocatalytic activity for H evolution can be mainly attributed to the matched energy level and heterojunction structure which could improve the photo-generated charge carriers separation and transfer. This work implies that construction of heterojunctions with a wide band gap semiconductor is a feasible strategy for enhancement of photocatalytic activity of CN materials.