Fabrication of binary Ag3PO4 photocatalysts for enhanced photocatalytic degradation: Effect of PEDOT hole conductor and hybridized 1 T-containing MoS2 electron conductor

Abstract

Photocatalytic activity of Ag3PO4 has been improved through the addition of poly(3,4-ethylenedioxythiophene) (PEDOT) hole conductor or 1 T-containing MoS2 electron conductor. The binary Ag3PO4 composites were synthesized using a facile ion-exchange and chemisorption method. The photocatalytic performance of the composites was evaluated through the photodegradation of methylene blue (MB) and tetracycline (TC) under solar light irradiation. the addition of PEDOT or 1 T-containing MoS2 significantly improves the visible light absorption and effectively enhances the charge separation of photogenerated electrons/holes. Photocatalytic mechanisms are proposed for both the PEDOT/Ag3PO4 and MoS2/Ag3PO4 composites. We demonstrate that the PEDOT/Ag3PO4 composite exhibits a Z-scheme mechanism where the conversion of oxygen (O2) to superoxide radical (∙O2–) occurs at the PEDOT and the formation of hydroxyl radical (∙OH) occurs at the Ag3PO4. For the MoS2/Ag3PO4 composite, the 1 T-containing MoS2 acts as a co-catalyst to accept the photogenerated electrons from the Ag3PO4. Also, due to its metallic property, the1T-containing MoS2 reduces charge transfer resistance. As a result, the MoS2/Ag3PO4 exhibits superior MB and TC photodegradation performances, giving efficiencies of 99% and 93%, respectively, under solar light irradiation.