Significant visible-light photocatalytic enhancement in Rhodamine B degradation of silver orthophosphate via the hybridization of N-doped graphene and poly(3-hexylthiophene)

Organic pollutants as typical water contaminants are potentially harmful to human health. In this study, we suggested that the novel Ag 3 PO 4 /N-doped graphene (NG)/Poly(3-hexylthiophene) (P3HT) composites can remove the organic dye Rhodamine B (RhB) from water. This Ag 3 PO 4 -based photocatalyst was synthesized via a facile method and subsequently characterized by XRD, SEM, TEM, XPS, Raman spectroscopy, PL spectroscopy, and UV–vis DRS. The photocatalytic activity of Ag 3 PO 4 /NG/P3HT composites is significantly higher than that of pristine Ag 3 PO 4 , Ag 3 PO 4 /NG, and Ag 3 PO 4 /P3HT for RhB degradation under visible light irradiation, especially the kinetic constant of Ag 3 PO 4 /NG/P3HT is more than 6 times of pristine Ag 3 PO 4 . The reactive oxygen species trapping experiments indicate that the degradation of RhB over the Ag 3 PO 4 /NG/P3HT composites mainly results from the holes oxidation and superoxide radical reduction. Besides, Ag 3 PO 4 /NG/P3HT composites exhibit better recyclability and stability than pristine Ag 3 PO 4 . Furthermore, the photocatalytic mechanism of Ag 3 PO 4 /NG/P3HT composites for RhB degradation under visible light was proposed as the synergistic effect of irradiated Ag 3 PO 4 , P3HT and NG sheets on the effective separation of photogenerated electron-hole pairs, and the enhancement of visible light absorbance.