▎ 摘　　要

A novel ternary nanocomposite comprising mesoporous WO3, Mn3O4 nanoparticles and N-doped graphene was prepared by a one-pot deposition method. The nanocomposite was characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The results demonstrated that the Mn3O4 nanoparticles had been successfully hybridized with the mesoporous WO3 and the WO3/Mn3O4 hybrid was well dispersed on the surface of N-doped graphene with superior interactions. The nanocomposite exhibits higher photocatalytic activity for water oxidation than the individual mesoporous WO3 and WO3/Mn3O4 catalysts. The amount of oxygen evolution from the optimized heterostructural photocatalyst (1.5 wt% Mn3O4 and 2 wt% N-doped graphene) was 294 mu mol g(-1), which was about 3.6 times as high as that from m-WO3. The heterostructure formed between Mn3O4 and m-WO3 enhances photogenerated electron/hole transfer and restrains the recombination of charges greatly. N-doped graphene in the nanocomposite acting as an excellent electron acceptor and mediator also contributes to the increase in photocatalytic performance by promoting the separation and transfer of photogenerated charges. This study suggests a promising method to enhance photocatalytic activity by combining the heterostructural WO3/Mn3O4 hybrid with graphene in a ternary system.