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

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.