Photocatalytic degradation of organic pollutants and inactivation of pathogens under visible light via CoOx surface-modified Rh/Sb-doped SrTiO3 nanocube

Visible light-active rhodium and antimony-co-doped SrTiO 3 nanocubes (Rh/Sb:SrTiO 3 NCs) were synthesized at low temperatures from Rh/Sb:TiO 2 nanorods by the molten salt flux method. The effects of different calcination temperatures (700, 800, and 900 °C) and addition of transition metal oxides (NiO x , CoO x , and CuO x ) on the photocatalytic properties of the Rh/Sb:SrTiO 3 NCs were studied. The phase composition and morphology of the Rh/Sb:SrTiO 3 NC photocatalysts (after calcination) were characterized using standard analytical techniques. The synergistic effect of the metal oxides and Rh/Sb:SrTiO 3 NCs boosted the photocatalytic degradation of orange II dye and bisphenol A as well as the inactivation of bacteria. 2 wt% CoO x -loaded Rh/Sb:SrTiO 3 photocatalyst showed higher photocatalytic performance for the degradation of orange II (96.3%) and bisphenol A (87%) in aqueous solution than Ni (2 wt%) and Cu (2 wt%)-loaded Rh/Sb:SrTiO 3 NC composites. In addition, inactivation of Escherichia coli (96%) and Staphylococcus aureus (97.1%) was achieved over CoO x (2 wt%)-loaded Rh/Sb:SrTiO 3 for 2 h under visible light irradiation ( λ ≥ 420 nm). Further, scavenging experiments confirmed that superoxide anion radicals ( · O 2 − ) and holes (h + ) are the major active species and OH · is a minor species responsible for the photocatalytic degradation of the studied organic pollutants. The synthetic strategy presented here offers a novel approach to the design of highly active visible light active photocatalysts for the removal of organic pollutants and inactivation of bacteria in wastewater. Graphical abstract