High Surface Area SnO2 -Ta2 O5 Composite for Visible Light-driven Photocatalytic Degradation of an Organic Dye.

SnO2 -Ta2 O5 nanocomposite was synthesized by a facile coprecipitation method and further calcined to obtain crystalline powder. Phase formation, morphology, bandgap and photocatalytic properties were analyzed using powder X-ray diffraction, scanning electron microscopy, UV-Vis diffused reflectance spectroscopy, BET surface area and Raman spectroscopy, respectively. Effect of calcination temperature on the crystallinity of the composite was studied. The as-prepared samples of SnO2 , Ta2 O5 and SnO2 -10wt%Ta2 O5 composite as well as the calcined composite sample were tested for photocatalytic activity for methylene blue dye degradation under visible light. Photocatalytic studies reveal that the as-prepared SnO2 -10wt%Ta2 O5 composite showed the best photocatalytic activity for the degradation of methylene blue (MB) by harvesting visible-light radiation efficiently. Further mineralization of methylene blue, estimated by COD analysis, is found to have degraded with an efficiency of 91.6%. The study demonstrates that heterostructure of SnO2 -Ta2 O5 nanocomposite could be applied in photocatalytic purification of organic pollutants.