Efficient photocatalytic H2 evolution over 2D/2D S-scheme NiTe2/g-C3N4 heterojunction with superhydrophilic surface

Rapid separation of charge carriers and fast kinetics of surface reaction are two essential prerequisites to achieve the efficient H-2 evolution from photocatalytic water splitting. In this work, a 2D/2D S-scheme NiTe2/g-C3N4 heterojunction was constructed by an in-situ deposition strategy using g-C3N4 nanosheets as substrate. The optimal composite exhibited a H-2 evolution rate of 2540.4 mu mol.g(-1).h(-1), which was 23.4 and 17.8 times higher than that of pristine g-C3N4 and NiTe2, respectively. Investigation indicates that the 2D contact interface and the built-in electric field between g-C3N4 and NiTe2 can accelerate the migration of photogenerated carriers, simultaneously, S-scheme charge transfer route endows the reserved electrons and holes with strong redox ability. What's more, the hydrophilicity of catalyst surface is remarkably improved after acid treatment, the H-2 evolution rate can be boosted to 12902.9 mu mol.g(-1).h(-1). This work provides a new application of telluride and an effective method to enhance the H-2 evolution activity of the catalysts.