MoSe₂-NiSe dual co-catalysts modified g-C₃N₄ for enhanced photocatalytic H₂ generation

Solar energy conversion into hydrogen (H₂) energy has attracted much attention. However, the low light utilization rate and fast carrier recombination of photocatalysts extremely limit the practical application of photocatalytic H₂ production. In this paper, MoSe₂-NiSe with abundant active sites and interfacial electronic structures as dual co-catalysts were assembled on g-C₃N₄ nanosheets (NSs) vis a solvothermal reaction process. MoSe₂-NiSe/g-C₃N₄ NSs composite exhibited improved light absorption and photoelectrochemical properties. The photocatalytic H₂ production rate of MoSe₂-NiSe/g-C₃N₄ composite achieved 2379.04 μmol·h^-1·g^-1, which is 99.25, 1.44, and 3.67 times those of pure g-C₃N₄ nanosheets (23.97 μmol·h^-1·g^-1), MoSe₂/C₃N₄ (1654.57 μmol·h^-1·g^-1), and NiSe/C₃N₄ (649.08 μmol·h^-1·g^-1), respectively. The apparent quantum efficiency (AQE) value of MoSe₂-NiSe/g-C₃N₄ achieved 4.07 % under light at λ = 370 nm. The corresponding characterization and experiments proved that 2D ultrathin g-C₃N₄ NSs with a large surface area and short charge-transfer distance could facilitate light scattering and the transport of photoexcited electrons. MoSe₂-NiSe, as a dual co-catalyst, showed strong electronic synergistic interaction between the interfaces, thus improving the conductivity and promoting the electron transfer process.