Hydrogen evolution from MoSe2/WO3(0 0 1) heterojunction by photocatalytic water splitting: A density functional theory study

Highlights: • MoSe₂/WO₃(0 0 1) heterojunction (MWH) with wide light-absorption spectra was designed. • The photocatalytic mechanism of MWH and the migration pathways of photogenic carriers was revealed. • MWH exhibited superior oxidation (3.302 eV) and reduction (−0.128 eV) properties, which could be used to photocatalytic water splitting for hydrogen evaluation. Photocatalytic water splitting for hydrogen evaluation as a green approach for energy production has received extensive attention from researchers. The strongly reducing single layer MoSe₂ and oxidizing WO₃(0 0 1) were constructed as a MoSe₂/WO₃(0 0 1) heterojunction (MWH). The electronic structure and optical properties of the MWH were calculated and analyzed using the density functional theory (DFT) to reveal the internal causes of the photogenerated carrier migration path and the photocatalytic mechanism. The electronic structure and optical absorption analysis showed that MoSe₂ and WO₃ contributed to the valence band maximum (VBM) and conduction band minimum (CBM) of MWH, respectively, narrowing the bandgap and broadening the optical absorption range. The energy band bending results indicated that the MWH was a Z-scheme photocatalytic heterojunction. Through the segregation of the oxidation (WO₃) and reduction sites (MoSe₂), photogenerated electrons and holes could be separated, and the formation of a built-in electric field inhibited the recombination of photogenerated carriers. Given that the MWH exhibited superior oxidation (3.302 eV) and reduction (−0.128 eV) properties, it has great potential for applications in the field of photocatalytic hydrogen production.