The ultra-low energy barrier for photocatalytic hydrogen evolution by the creation of Z-scheme SnC/PtSe2 heterojunctions: First-principles calculation

Abstract

In this study, we designed a vertical heterojunction of SnC/PtSe2 to lower the energy barrier for the photocatalytic hydrogen evolution reaction (HER). Through first-principles calculations, we systematically explored the electronic structure properties, band bending, photocatalytic performance, and light absorption. Our results indicate that photo-generated carriers transfer along the Z-path, exhibiting strong reduction ability and effective carrier utilization. The observed electric field and band bending at the interface facilitate the recombination of photo-generated electron-hole pairs between layers. As a result, photo-generated electrons accumulate on SnC, enabling the continuation of the HER. Specifically, the SnC/PtSe2 heterojunction demonstrates a significantly reduced energy barrier of 0.081 eV for the HER. Furthermore, SnC/PtSe2 heterojunctions also greatly enhance the absorption of infrared and visible light. Our findings provide valuable insights for the development of catalysts in hydrogen production through water photolysis.