Catalysis Today, Vol.380, 25-31, 2021
Substitutionally rhodium(IV)-doped titania showing photocatalytic activity toward organics oxidation under visible-light irradiation
In this study, an aqueous solution containing rhodium(IV) (Rh(IV)) was prepared by oxidation of rhodium(III) (Rh(III)) with solid sodium bismuthate in nitric acid and then used as a medium for hydrothermal titania preparation to obtain rhodium-doped titania (Rh-TiO2) composite. Rh(IV) species were observed in Rh-TiO2 in XPS analysis. Effect of rhodium/titanium molar ratio (Rh/Ti) on the photocatalytic activity was studied. The obtained characteristics suggest successful rhodium substitution and doping of titania to give visible-light absorption. The Rh-TiO2 composite exhibits enhanced photocatalytic activity for acetic acid decomposition and 2propanol oxidation under UV-vis (> 290 nm) and visible-light (> 450 nm) irradiation, respectively. The enhanced photocatalytic activity is attributable to the visible-light absorption induced by rhodium doping. These results indicate that Rh-TiO2 photocatalyst materials could be promising materials for high-efficiency photooxidation reactions under visible-light irradiation.