Synergetic tuning of photocatalytic activity and photostability of Ag3PO4 via yttrium doping, carbon quantum dots and BiVO4 for atenolol degradation

In this study, Y-doped Ag 3 PO 4 , carbon quantum dots (CQDs), BiVO 4 were used to synthesize Z-scheme Y-Ag 3 PO 4 /CQDs/BiVO 4 . X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT-IR) and UV–vis diffuse reflectance spectra (DRS) were employed to probe into the crystalline structure, morphology, optical property and chemical composition of Y-Ag 3 PO 4 /CQDs/BiVO 4 . The kinetic constant of the prepared Y-Ag 3 PO 4 /CQDs/BiVO 4 was approximately 2.8 times that of pristine Ag 3 PO 4 for atenolol degradation. The degradation of atenolol mainly depended on the excited holes, •OH and •O 2 − . The photocatalysis mechanism of Y-Ag 3 PO 4 /CQDs/BiVO 4 conforms to the Z-scheme mechanism deduced by reactive species trapping experiment, electron spin resonance (ESR) and photoelectrochemical measurement (photocurrent response and EIS). The introduction of yttrium, CQDs and BiVO 4 significantly promoted the photogenerated carriers separation of Ag 3 PO 4 and inhibited the photogenerated electron-holes pairs recombination of Ag 3 PO 4 during the degradation of atenolol. Oxygen defects caused by the doping of Y 3+ into Ag 3 PO 4 were the centers of capture of photogenerated electrons to generate •O 2 − , inhibiting the recombination of photogenerated electron-holes pairs and the photocorrosion of Ag 3 PO 4 .