Novel Ag3PO4 modified tubular carbon nitride with visible-light-driven peroxymonosulfate activation: A wide pH tolerance and reaction mechanism

Abstract

• New Ag 3 PO 4 modified tubular porous C 3 N 4 photocatalyst was subsequently fabricated. • A wide pH tolerance (3.0–9.0) was shown in the Vis/10%Ag 3 PO 4 @TPCN 12 /PMS system. • The main reactive species in Vis/10%Ag 3 PO 4 @TPCN 12 /PMS system under both acidic and alkaline conditions were investigated. • The reaction mechanism in Vis/10%Ag 3 PO 4 @TPCN 12 /PMS system dominated by nonradical oxidation was proposed. In this study, we fabricated the novel Ag 3 PO 4 modified tubular porous carbon nitride (Ag 3 PO 4 @TPCN 12 ) photocatalyst and evaluated its photocatalytic activity under the visible light irradiation in the presence of peroxymonosulfate (PMS) through carbamazepine (CBZ) degradation in water. The apparent rate constant in Vis/10%Ag 3 PO 4 @TPCN 12 /PMS system (0.0927 min −1 ) exhibited great superiority over that in Vis/TPCN 12 /PMS (0.0227 min −1 ), Vis/Ag 3 PO 4 /PMS (0.0019 min −1 ), and even Vis/(Ag 3 PO 4 + TPCN 12 )/PMS (0.0646 min −1 ) systems. Importantly, a wide pH tolerance (3.0–9.0) was shown in Vis/10%Ag 3 PO 4 @TPCN 12 /PMS system. Multifarious reactive species involving SO 4 •− , HO • , 1 O 2 , and photo-generated holes primarily responsible for the CBZ degradation were verified. The degradation pathways of CBZ were proposed, and the ecotoxicity of CBZ degradation products was assessed. In general, the Vis/10%Ag 3 PO 4 @TPCN 12 /PMS system was capable of high stability and benign resistance of water matrix, showing a hopeful practical application potential for organic compounds degradation in water.