A solar light-induced photo-thermal catalytic decontamination of gaseous benzene by using Ag/Ag3PO4/CeO2 heterojunction

The effectively decontamination for atmosphere VOCs is getting more important whereas it is general facing the issues such as technical difficulties and high energy consumption. In this work, a Z-scheme Ag/Ag3PO4/CeO2 heterojunction was prepared with a precipitation method and was applied to decompose gaseous benzene at very convenient ambient conditions. The prepared composite presents a 90.18% removal rate and 74.17% TOC efficiency within 3 h solar light irradiation at an initial 600 ppm benzene concentration. A photo-catalytic mechanism superimposed with solar light induced thermo-catalysis is proposed. Ag3PO4 that has great solar light absorptive capacity is used as the photocatalytic component and CeO2 is used as thermo-catalytic substrate due to its good thermo-conductivity in lower temperature. Ag-0 produced from an in situ reduction of Ag3PO4 is used as an electronic relay platform to form a Z-type heterojunction together with Ag3PO4 and CeO2. Lots of vacancies of CeO2 contribute to the enhanced pre-adsorption towards to VOCs. The assembled Z-scheme Ag/Ag3PO4/CeO2 heterojunction is specially effectively for the separation of the photo-excited electrons and holes in space and maintains the highly redox potentials to decontaminate VOCs. Meanwhile, the composite is diverse, also having good oxidative power for HCHO, and thus could be a kind of promising material to purify VOCs in the convenient atmospheric environment.