Two-dimensional PtSe2/hBN vdW heterojunction as photoelectrocatalyst for the solar-driven oxygen evolution reaction: A first principles study

[Display omitted] •Six possible stacking patterns of the PtSe2/hBNC vdW heterojunction are studied.•PtSe2/hBNC has good thermodynamic, kinetic and mechanical stability.•Type-Ⅱ heterojunction has effectively enhanced the photocatalytic activity.•PtSe2/hBNC possesses marvelous carrier mobility and OER efficiency. Designing and researching suitable photoelectrocatalyst for water splitting is crucial for the utilization of renewable and inexhaustible solar energy but remains a huge conundrum. Here, using first principles calculations, the two-dimensional PtSe2/hBN heterojunction was first conceived. However, the rapid recombination of electrons and holes will inhibit the visible light catalytic efficiency of the heterojunction. In order to realize effective spatial separation of electrons and holes of the heterojunction, we tuned the band gap by doping two carbon atoms on the hBN monolayer to obtain the type-Ⅱ PtSe2/hBNC heterojunction. Then through the comprehensive researches on structural, electronic and optical properties, it was found that the structure possesses excellent carrier mobility and exhibits a great oxygen evolution reaction performance with a low overpotential of 0.76 eV, which is an ideal photoelectrocatalyst and exhibits great light absorption performance. In this study, the possible mechanism of doped PtSe2/hBNC vdW heterojunction to promote photocatalysis and oxygen evolution ability was explained, which may pave the way for the practical design of more solar-driven high-quality water splitting photoelectrocatalysts.