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.