Nitrogen-doped carbon quantum dots/AgPO complex photocatalysts with enhanced visible light driven photocatalytic activity and stability.

Novel nitrogen-doped carbon quantum dots/AgPO (NCQDs/AgPO) complex photocatalysts were synthesized by a facile precipitation method at room temperature. The physical and chemical properties of AgPO and NCQDs/AgPO 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/AgPO composite exhibited much higher activity than the pure AgPO for eliminating methyl orange and bisphenol A solution under visible light (λ>420nm). Moreover, in the cyclic experiments, the 3-NCQDs/AgPO 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 AgPO→NCQDs→Ag in the photocatalytic process, leading to effective charge separation of AgPO.