Synthesis of Ag(3)PO(4)/Ag/g-C(3)N(4) Composite for Enhanced Photocatalytic Degradation of Methyl Orange

In this study, we have successfully constructed Ag(3)PO(4)/Ag/g-C(3)N(4) heterojunctions via the hydrothermal method, which displays a wide photo-absorption range. The higher photocurrent intensity of Ag(3)PO(4)/Ag/g-C(3)N(4) indicates that the separation efficiency of the photogenerated electron–hole pairs is higher than that of both Ag(3)PO(4) and Ag/g-C(3)N(4) pure substances. It is confirmed that the efficient separation of photogenerated electron–hole pairs is attributed to the heterojunction of the material. Under visible light irradiation, Ag(3)PO(4)/Ag/g-C(3)N(4)-1.6 can remove MO (~90%) at a higher rate than Ag(3)PO(4) or Ag/g-C(3)N(4). Its degradation rate is 0.04126 min(−1), which is 4.23 and 6.53 times that of Ag/g-C(3)N(4) and Ag(3)PO(4), respectively. After five cycles of testing, the Ag(3)PO(4)/Ag/g-C(3)N(4) photocatalyst still maintained high photocatalytic activity. The excellent photocatalysis of Ag(3)PO(4)/Ag/g-C(3)N(4)-1.6 under ultraviolet-visible light is due to the efficient separation of photogenerated carriers brought about by the construction of the Ag(3)PO(4)/Ag/g-C(3)N(4) heterostructure. Additionally, Ag(3)PO(4)/Ag/g-C(3)N(4) specimens can be easily recycled with high stability. The effects of hydroxyl and superoxide radicals on the degradation process of organic compounds were studied using electron paramagnetic resonance spectroscopy and radical quenching experiments. Therefore, the Ag(3)PO(4)/Ag/g-C(3)N(4) composite can be used as an efficient and recyclable UV-vis spectrum-driven photocatalyst for the purification of organic pollutants.