Efficient interfacial charge transfer in the MoSe2/SPtSe heterostructure improves the efficiency of hydrogen production from water splitting: A S-scheme photocatalyst.

The novel S-scheme heterostructure shows its superiority in photocatalysis due to its high efficiency of charge transfer. In this paper, we compared the mechanical, electronic, optical and transport properties of two different contact modes of heterostructure structures of MoSe 2 /Janus PtSSe and their applications in photocatalytic water splitting through density functional theory. The results show that the charge transfer of MoSe 2 /SePtS heterostructures occurs between layers. On the contrary, the charge separation of MoSe 2 /SPtSe heterostructures is significant, and there are internal electric fields and suitable band arrangements at the interface from MoSe 2 to SPtSe direction, forming S-scheme photocatalysts. Compared with the MoSe 2 /SePtS heterostructure, the MoSe 2 /SPtSe heterostructure has higher carrier mobility. Furthermore, the MoSe 2 /SPtSe heterostructure has good light absorption in the visible range, and the solar-to-hydrogen (STH) efficiency is as high as 7.97%. Gibbs free energy calculation shows that the overpotential η OER = 1.63 V (pH = 0) decreases to η OER = 1.11 V(pH = 7) with the increase of pH value. We expect that our results can provide valuable insights into the rational design of efficient heterostructure in photocatalytic water splitting systems. [Display omitted] • MoSe 2 /SPtSe heterostructure with high carrier mobility. • The existence of charge transfer in the MoSe 2 /SPtSe heterostructure is advantageous. • MoSe 2 /SPtSe heterostructure is a S-scheme photocatalyst for water splitting. • The ηOER of MoSe 2 /SPtSe heterojunction decreased with the increase of pH. • MoSe 2 /SPtSe heterostructure has ultra-high STH efficiency (7.79%). [ABSTRACT FROM AUTHOR]