Fabrication of a novel high photocatalytic Ag/Ag3PO4/P25 (TiO2) heterojunction catalyst for reducing electron-hole pair recombination and improving photo-corrosion

Abstract

Noble metal Ag nanoparticles were deposited on Ag3PO4/P25 heterojunction structure by ultraviolet (UV) light induction to construct Ag/Ag3PO4/P25 double heterojunction catalyst for efficient decomposition of phenacetin (PNT). X-Ray Diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Raman and photoluminescence (PL) spectroscopy analyses were employed to evaluate the microstructure, chemical structure and photocatalytic activity of synthesized catalyst materials. PL spectroscopy analyses revealed that a considerable enhancement in photochemistry activity of Ag3PO4/P25 due to the deposition of Ag. The effects of Ag3PO4 mass ratios, operating conditions on PNT degradation and catalyst stability were also investigated. Results showed that Ag/10% Ag3PO4/P25 under the operating conditions of catalysts concentration of 0.5 g L-1 and pH of 9.0 with UV light irradiation displayed a better photocatalysis degradation performance. When the concentration of PNT was 20 mg L-1, the removal rate of PNT and TOC obtained from Ag/Ag3PO4/P25 system were up to 97 % and 83%, respectively. The removal rate of PNT drops from 97% to 85% between the first and last cycles after 60-min conversion. Ag/Ag3PO4/P25 with a high catalytic reaction efficiency was ascribed to the deposition of Ag. Ag is an electron acceptor and Ag3PO4 have excellent electron conductivity in a heterostructure, the novel Ag/Ag3PO4/P25 composite catalyst could reduce the recombination rate of electron-hole pairs and prolong the lifetime of photogenerated electrons.