Abstract
Porous TiO2 nanospheres decorated with plasmonic Ag nanoparticles effectively degrade ceftiofur sodium through UV–visible light activated •OH. Degradation products are not toxic. AgNPs enhances the charge separation at Ag/TiO2 interface.
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•Ag nanoparticles decorated porous TiO2 nanospheres are synthesized solvothermally.•Ag NPs traps excited electron and forbids the e−/h+ recombination.•Amplified •OH formation causes rapid oxidation of ceftiofur sodium (CFS).•Under visible light, porous Ag-TiO2 NSPs effectively oxidize CFS.•Oxidation products of CFS are not toxic.
In this study, 250 nm sized porous anatase TiO2 nanospheres (TiO2 NSPs) composed of ∼ 10 nm sized anatase TiO2 nanoparticles are obtained through a green synthetic route and their surfaces have been decorated with 3–4 nm sized plasmonic silver nanoparticles (AgNPs). Photoluminescence studies confirm that the AgNPs presence on TiO2 NSPs surface effectively inhibits the radiative charge recombination and thus facilitates charge separation process at the Ag-TiO2 NSPs interface, causing an enhanced photocatalytic activity. About 92% of the ceftiofur sodium (CFS) antibiotic taken initially is oxidized by Ag-TiO2 NSPs upon 90 min white light irradiation, while Ag loaded Degussa P25 TiO2 nanoparticles effects only 71% CFS oxidation. The synergistic effect given by plasmonic AgNPs and the continuous framework of anatase TiO2 NPs contributes to inhibit the electron-hole recombination in the Ag-TiO2 NSPs. Oxidation products of CFS in different water sources and their eco-toxicity effects identified through LC-MS and microtox-bioassays, respectively, indicate that the obtained oxidation products are non-toxic compared to pure CFS. Therefore, porous Ag-TiO2 NSPs could be successfully applied in photocatalytic oxidation technologies, exploiting sunlight for the effective removal of pharmaceutical pollutants from wastewater.