Design of a direct Z-scheme GeC/arsenene van der Waals heterostructure as highly efficient photocatalysts for water splitting.

The utilization of heterostructures as photocatalysts for water decomposition is a promising method to tackle contemporary environmental challenges. This research paper presents the design of a direct Z-scheme heterostructure utilizing a monolayer of GeC and a monolayer of arsenene, based on first-principle calculations. The photocatalytic efficiency of this GeC/arsenene van der Waals (vdW) heterostructure in a direct Z scheme has been investigated. The presence of a built-in electric field from the GeC monolayer to the arsenene monolayer has been established through an analysis of band alignment, work function, charge density, and Bader charge. The GeC/arsenene heterostructure exhibits excellent and robust optical absorption efficiency for the sunlight, alongside achieving the maximum solar-to-hydrogen (STH) energy conversion efficiency, amounting to 7.28%, under a biaxial strain of +4%. Furthermore, the Gibbs free energy changes in the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) of the GeC/arsenene heterostructure have been calculated. The outcomes indicate that the GeC/arsenene heterostructure is a feasible semiconductor for photocatalytic water splitting. Band edge positions and Z-scheme photocatalytic mechanism of the GeC/arsenene heterojunction. [Display omitted] • GeC/arsenene heterostructure has a built-in electric field from GeC to arsenene layer. • GeC/arsenene heterostructure exhibits a high optical absorption under biaxial tensile strain. • The highest solar-to-hydrogen efficiency of 7.28% is obtained under +4% strain. • High catalytic activity for the hydrogen evolution reaction is confirmed by free energy calculations. [ABSTRACT FROM AUTHOR]