Construction of a 2D Graphene-Like MoS₂/C₃N₄ Heterojunction with Enhanced Visible-Light Photocatalytic Activity and Photoelectrochemical Activity

A novel graphene-like MoS₂/C₃N₄ (GL-MoS₂/C₃N₄) composite photocatalyst has been synthesized by a facile ethylene glycol (EG)-assisted solvothermal method. The structure and morphology of this GL-MoS₂/C₃N₄ photocatalyst have been investigated by a wide range of characterization methods. The results showed that GL-MoS₂ was uniformly distributed on the surface of GL-C₃N₄ forming a heterostructure. The obtained composite exhibited strong absorbing ability in the ultraviolet (UV) and visible regions. When irradiated with visible light, the composite photocatalyst showed high activity superior to those of the respective individual components GL-MoS₂ and GL-C₃N₄ in the degradation of methyl orange. The enhanced photocatalytic activity of the composite may be attributed to the efficient separation of electron-hole pairs as a result of the matching band potentials between GL-MoS₂ and GL-C₃N₄. Furthermore, a photocatalytic mechanism for the composite material has been proposed, and the photocatalytic reaction kinetics has been measured. Moreover, GL-MoS₂/C₃N₄ could serve as a novel sensor for trace amounts of Cu²⁺ since it exhibited good selectivity for Cu²⁺ detection in water.