Photocatalytic activity of GaSSe/ WTe2 vdW heterstructure nanocatalyst: The first-principles study

Abstract

Photocatalytic production of hydrogen provides a feasible strategy to solve the energy crisis and environmental pollution problems. In this paper, the bilayer Ga2SSe/WTe2 vdW heterstructure is proposed to be an effective photocatalyst for hydrolysis by first-principle calculations. Structural stability analyses show that the bilayer Ga2SSe/WTe2 vdW heterstructure is energetically and dynamically stable. The electronic properties show that the bilayer Ga2SSe/WTe2 vdW heterstructure belongs to an indirect bandgap semiconductor (1.287 eV), which is conducive to the reduction of the chance of carrier complexation. Photocatalytic performance analysis shows that the energy band edge positions of bilayer Ga2SSe/WTe2 vdW heterstructure are suitable for photocatalytic hydrolysis in the range of PH = 0 ∼ 14. In addition, the bilayer Ga2SSe/WTe2 vdW heterstructure has higher UV and visible light absorption, larger built-in electric field, and smaller carriers, which effectively ensures the effective separation of photogenerated carriers and their rapid migration to the reactive sites for the redox reaction of water. The results provide valuable theoretical guidance for the synthesis of bilayer Ga2SSe/WTe2 vdW heterstructure and its potential application as a hydrolysis photocatalyst.