DFT Insight into the Photocatalytic Properties of PtSSe-Se vdW Heterostructure

Inspired by the high photoconversion efficiency of 2D nanomaterials, we designed novel vdW heterostructure PtSSe-Se for the solar mediated photocatalytic hydrogen production. We investigated basic electrical and optical characteristics using ab-initio Density Functional Theory (DFT) calculations. Further, we performed electrostatic potential calculation to evaluate band alignments of PtSSe and Se, which revealed the water splitting capacity of the heterostructure. Later, the Gibbs free energy analysis also shows the heterostructure construction reduced the barrier height for the water reduction reaction effectively. Our in-depth investigation revealed the synergistic effect of built in electric field in the Janus PtSSe structure as well as generated electric field due to the heterostructure model have significant role in improving the photocatalytic efficiency. The dual electric field creation due to this unique structure effectively suppressed the charge carrier recombination and lead to enhanced lifetime of charge carriers in this PtSSe-Se heterostructure. In addition to that, the decreased lattice mismatch, elevated visible light response and fast charge transfer are the other factors that enhanced the photocatalytic efficiency of this Janus-chalcogenide heterostructure in a better way.