Synthesis and characterization of Bi1.56Sb1.48Co0.96O7 pyrochlore sun-light-responsive photocatalyst

Novel nanostructure pyrochlore Bi1.56Sb1.48Co0.96O7 was successfully synthesized via solid state reaction method in air. The as-synthesized photocatalyst was characterized by X-ray diffraction, Scanning electron microscopy and UV-vis diffuse reflectance spectroscopy techniques. The results showed that the BSCO was crystallized with the pyrochlore-type structure, cubic crystal system and space group Fd3m. The average particle size and band gap for BSCO were D = 76.29 nm and E-g = 1.50 eV respectively. Under the optimum conditions for discoloration of the dye: initial concentration of 20 mg L-1 RhB, pH 7, 25 degrees C, 0.5 mL H2O2 and BSCO/dye mass ration of 1 g L-1, 97.77 and 90.16% of RhB were removed with BSCO/H2O2 photocatalytic system within 60 min of irradiation time under UVA- and SL irradiations respectively. Pseudo-second-order kinetic model gave the best fit, with highest correlation coefficients (R-2 >= 0.99). On the base of these results, the mechanism of the enhancement of the discoloration efficiency was discussed. (C) 2015 Elsevier Ltd. All rights reserved.