Unprecedented enhancement in visible-light-driven photoactivity of modified graphitic C₃N₄ by coupling with H₂WO₄

The modified graphitic carbon nitride (g-C₃N₄) nanosheets by coupling with H₂WO₄ are fabricated via an easy, mild and environmental-friendly impregnation method for the first time. Compared with bare g-C₃N₄ and H₂WO₄, the H₂WO₄/g-C₃N₄ composite shows significant enhancement in the visible-light-driven photoactivity toward the degradation of Rhodamine B (RhB). It is found that 10 wt.% H₂WO₄/g-C₃N₄ exhibits the best photocatalytic performance, with around 20 times higher activity than that of pure g-C₃N₄ nanosheets. The remarkably increased performance is mainly attributed to the existing synergistic interaction between H₂WO₄ and g-C₃N₄. The strong interaction could reduce the photoinduced electron-hole recombination and further improve the photocatalytic activity. Additionally, ^•O₂^- is the dominating reactive species for the degradation of RhB, which has been confirmed by the radical scavengers tests. The synthesized photocatalysts present super stability even after nine successive runs. Considering the low-cost, easy preparation process and ultra-high activity, the H₂WO₄/g-C₃N₄ photocatalyst can be served as a promising candidate for environment cleaning and waste water treatment.