Solvothermal synthesis and enhanced visible light photocatalytic activity of novel graphitic carbon nitride-Bi₂MoO₆ heterojunctions

Novel graphitic carbon nitride (C₃N₄)-Bi₂MoO₆ heterojunctions with different contents of Bi₂MoO₆ nanosheets were in situ synthesized by a simple solvothermal method. The resulting C₃N₄-Bi₂MoO₆ heterojunctions possess enhanced absorption within the visible light range compared with pure C₃N₄. Meanwhile, these C₃N₄-Bi₂MoO₆ heterojunctions also exhibit much higher photocatalytic activity for methyl orange (MO) degradation than those of single C₃N₄ and Bi₂MoO₆, as well as Degussa P25. Significantly, the optimum photocatalytic activity of the 0.2C₃N₄-0.8Bi₂MoO₆ heterojunction is 3.56 and 3.45 times faster than those of either individual C₃N₄ or Bi₂MoO₆. Based on the trapping experiment results, we believe that photogenerated holes and superoxide radicals O₂^- play a major role in C₃N₄/Bi₂MoO₆ heterogeneous system under visible light irradiation. What is more, the heterojunction displays excellent stability and reusability. This work provides a promising strategy for constructing more C₃N₄ based heterojunctions.