Exploring hierarchical porous silica-supported Ag₃PO₄ as high-efficient and environmental-friendly photocatalytic disinfectant

Abstract

Silver orthophosphate (Ag3PO4) is an attractive photocatalytic catalyst for disinfection and degradation, but its instability arising from silver release generates significant environmental issue. Aiming to develop a highly efficient and environmental-friendly catalyst, we synthesized Ag3PO4 nanoparticle incorporated hierarchical porous silica (Ag3PO4@h-SiO2) as a novel high-performance photocatalytic catalyst without observed silver release. Brain-like hierarchical porous SiO2 (h-SiO2) brings a scaffold support with high surface areas, and the h-SiO2 surface modified thiols are able to anchor in situ formed 10 nm Ag3PO4 to eliminate silver release. Systematic investigations revealed that because of its structural advantages, Ag3PO4@h-SiO2 show excellent disinfection and degradation ability under visible-light irradiation and stable characteristics without obviously observed silver leaching during photo-oxidation operation. In-depth scavenger study reveals Ag3PO4@h-SiO2 as an effective semiconducting photocatalyst stimulates the production of photo-generated reactive species, which dominate its distinguished disinfection performance via photo-oxidation. Graphical abstract: Ag3PO4 are anchored to thiol modified hierarchical porous SiO2 to produce a visible-light responsive photocatalyst of Ag3PO4@h-SiO2. The enhanced catalytic sites and surface areas promote pathogen disinfection, and the structure advantages minimize silver release to environment. Both H2O2 and holes being generated in photocatalysis dominate overall disinfection activity.