Enhanced Photocatalytic Degradation of Organic Pollutants and Inactivation of Listeria monocytogenes by Visible Light Active Rh-Sb Codoped TiO₂ Nanorods

In this work, we prepared visible-light active and rhodium and antimony codoped rutile TiO₂ nanorods (Rh-Sb:TiO₂ NR) for the degradation of organic pollutants and inactivation of microbial pathogens. The Rh-Sb:TiO₂ NR sample showed a shift in the absorption band in the visible light region (650 nm). Initially, photocatalytic activity of the Rh-Sb:TiO₂ NR was hindered due to its poor surface properties. To improve the surface quality of the less active Rh-Sb:TiO₂ NR photocatalyst, the effect of the acid treatment and Cu_xO impregnation on the Rh-Sb:TiO₂ NR were evaluated (Cu_xO/A-Rh-Sb:TiO₂ NR). The photocatalytic activity of the Cu_xO/A-Rh-Sb:TiO₂ NR photocatalyst was remarkably higher than that of the as-prepared sample. The improved photocatalytic activity of less active Rh-Sb:TiO₂ NR is due to the synergistic effect of acid treatment and finely dispersed Cu_xO nanoparticles which improve the charge transfer near the interface of the A-Rh-Sb:TiO₂ NR photocatalyst toward Cu_xO nanoparticles. Deconvolution of Cu results indicated that Cu_xO have mixed phase of 2+ and 1+ oxidation state which eases the charge transfer at the conduction band of photocatalyst. The optimization of Cu_xO loading was achieved by measuring the photocatalytic degradation efficiencies at controlled Cu concentrations on the A-Rh-Sb:TiO₂ NRs. Furthermore, the optimized Cu_xO sample was used for photocatalytic degradation of bisphenol A (BPA) and inactivation of L. monocytogenes pathogen. This work provides an efficient visible light photocatalyst for a broad range of environmental applications, such as pathogenic bacterial inactivation and decomposition of organic pollutants.