Conventional hexagonal dimolybdenum carbide(Mo2C)as a good cocatalyst has been widely applied for the enhanced photocatalytic hydrogen production of various photocatalysts.Compared with the hexag-onal Mo2C,however,the investigation about cubic molybdenum carbide(MoC)is still very limited in photocatalytic field.In this study,carbon-coated cubic molybdenum carbide(MoC@C)nanoparticle was synthesized and used as an effective cocatalyst to improve the H2-evolution efficiency of TiO2.The cubic MoC@C can be obtained by adjusting the mass ratio of C3N3(NH2)3 to(NH4)6Mo7O24(2∶1)and controlling the calcination temperature to 800 ℃.When the above cubic MoC@C nanoparticles were evenly loaded on the TiO2 via a sonication-assisted deposition,a homogeneous composite of TiO2/MoC@C was formed due to the strong coupling interface between TiO2 and cubic MoC nanoparticles.More importantly,the highest H2-production rate of TiO2/MoC@C reached 504 μmol h-1 g-1(AQE=1.43％),which was 50 times as high as that of the pure TiO2.The enhanced performance of TiO2/MoC@C can be attributed to the synergistic effect of carbon layer as an electron mediator and the cubic MoC as interfacial H2-evolution active sites.This work provides a feasible guideline to develop high-efficiency Mo-based cocatalysts for potential applications in the H2-evolution field.