Ag3PO4 nanocrystals and g-C3N4 quantum dots decorated Ag2WO4 nanorods: ternary nanoheterostructures for photocatalytic degradation of organic contaminants in water

Abstract

Visible-light-driven Ag₃PO₄/graphite-like carbon nitride/Ag₂WO₄ photocatalysts with different weight fractions of Ag₃PO₄ were synthesized. Ag₂WO₄ nanorods with a scale of 500 nm to 3 μm were prepared by using a hydrothermal reaction. Via a facile deposition–precipitation technique, graphite-like carbon nitride (g-C₃N₄) quantum dots and Ag₃PO₄ nanocrystals were then deposited onto the surface of Ag₂WO₄ nanorods sequentially. Under visible-light irradiation (λ > 420 nm), the Ag₃PO₄/g-C₃N₄/Ag₂WO₄ nanorods degraded Rh B efficiently and displayed much higher photocatalytic activity than that of pure Ag₂WO₄ and the g-C₃N₄/Ag₂WO₄ composite, and the Ag₃PO₄/g-C₃N₄/Ag₂WO₄ hybrid photocatalyst with 30 wt% of Ag₃PO₄ exhibited the highest photocatalytic activity. The quenching effects of different scavengers demonstrated that reactive h⁺ and ·O²⁻ played the major roles in Rh B degradation. It was elucidated that the excellent photocatalytic activity of Ag₃PO₄/g-C₃N₄/Ag₂WO₄ for the degradation of Rh B under visible light (λ > 420 nm) can be ascribed to the efficient separation of photogenerated electrons and holes through the Ag₃PO₄/g-C₃N₄/Ag₂WO₄ heterostructure.