MoSe-NiSe dual co-catalysts modified g-CN for enhanced photocatalytic H generation.

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