Nitrogen-doped carbon quantum dots/Ag₃PO₄ complex photocatalysts with enhanced visible light driven photocatalytic...

Novel nitrogen-doped carbon quantum dots/Ag₃PO₄ (NCQDs/Ag₃PO₄) complex photocatalysts were synthesized by a facile precipitation method at room temperature. The physical and chemical properties of Ag₃PO₄ and NCQDs/Ag₃PO₄ photocatalysts were detected through X-ray powder diffraction, field emission scanning electron microscopy, UV-vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy and electron spin resonance techniques. The as-prepared 3-NCQDs/Ag₃PO₄ composite exhibited much higher activity than the pure Ag₃PO₄ for eliminating methyl orange and bisphenol A solution under visible light (λ>420nm). Moreover, in the cyclic experiments, the 3-NCQDs/Ag₃PO₄ exhibited an excellent stability for the decolorization of methyl orange at some level. This suggested that NCQDs played an important role in the process of degradation. The function of NCQDs was discussed and a new mechanism was put forward for the degradation of methyl orange. The high activities and stability were attributed to the transfer of photogenerated charges through the vector of Ag₃PO₄→NCQDs→Ag in the photocatalytic process, leading to effective charge separation of Ag₃PO₄.