Photocatalytic degradation of ceftiofur sodium in the presence of gold nanoparticles loaded TiO2 under UV–visible light

• Gold nanoparticles loaded TiO2 is prepared and characterized.
• Au–TiO2 exhibit excellent photocatalytic degradation of CFS under UV–visible light.
• Sulfate radicals predominantly formed in Au–TiO2–PMS system.
• CFS and its degradation intermediates decompose simultaneously and unselectively.

In this work, gold nanoparticles loaded TiO2 (Au–TiO2) photocatalyst has been prepared through deposition–precipitation method and characterized using XRD, transmission electron microscopy, UV–visible spectroscopy and photoluminescence spectroscopy techniques. The efficacy of the Au–TiO2 towards the photocatalytic oxidation of ceftiofur sodium (CFS), a third-generation cephalosporin antibiotic, under UV–visible light has been studied. The Au–TiO2 exhibits 95% and 65% CFS degradation within 2 h under UV–visible and visible-light irradiation, respectively, while TiO2 effects <5% CFS degradation in the visible-light. The photocatalytic degradation of CFS in the presence of electron acceptors is investigated and the degradation mechanisms are proposed. Peroxomonosulfate (PMS) produces highly active sulfate radicals during the heterogeneous activation of PMS by Au–TiO2 under simulated solar radiation. HPLC analysis confirms the simultaneous abatement of CFS and its degradation intermediates. The extent of mineralization of CFS is evaluated using total organic carbon analysis.

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