Influence of Sn ion doping on the photocatalytic performance of V₂O₅ nanorods prepared by hydrothermal method

Pure and different concentrations of Sn⁴⁺ doped V₂O₅ (Sn:V₂O₅) nanorods were synthesized by hydrothermal method. The Sn:V₂O₅ nanorods obtained were orthorhombic in structure. No secondary phase was observed up to 10% of Sn doping, but beyond that, there evolved a secondary phase of SnO₂. Microstructural analysis revealed the morphology of V₂O₅ as nanorods and platelets like structure. Presence of V, O and Sn elements in the samples was confirmed by energy dispersive spectroscopy. The V₂O₅ nanorods have shown a strong absorption in the visible region and the band gap energy was obtained to be varying from 2.21 to 2.26 eV as a function of Sn ion doping. Photocatalytic studies on methylene blue (MB) under visible light irradiation showed that the 3% Sn:V₂O₅ had effectively degraded MB up to a maximum degradation of 96% and further increase in Sn content had decreased the photodegradation due to higher recombination rate of photogenerated electrons. The mechanism of photodegradation was completely understood and the OH^· radicals have played a dominant role in the photodegradation of the organic dyes. (paper)