A novel thin film Sn3O4 supported titanium (Sn3O4/Ti) successfully applied in the photoelectrocatalytic degradation of Acid Yellow 17 under visible light

Photoelectrocatalysis is a powerful method resulting from the combination of heterogeneous photocatalysis and electrochemical techniques, in which a semiconductor is irradiated by light energy equal or greater than its band gap and simultaneously biased by a gradient potential. Within the numerous types of semiconductors used as photocatalysts, tin oxides with different forms (SnO, SnO2 and Sn3O4), present wide-spread applications, because of its abundant availability and non-toxicity. The aim of this work was to perform the synthesis of a Sn3O4 ordered structure under mild operational conditions to further apply it in the photoelectrocatalytic degradation of a dye, taken Acid Yellow 17 as a model of textile dye treatment. The hierarchical form of Sn3O4, with the flower-like nanostructure (Fig. 1) with triclinic Sn3O4/Ti, was successfully prepared using microwave-assisted hydrothermal method at pH 6, in 150 oC. The as-prepared Sn3O4 was deposited in the titanium substrate using spin coating methods. The Sn3O4 /Ti nanostructure demonstrated high photocatalytic activity (Fig. 2) in the visible wavelength (λ>390 nm), calculated band gap of energy 2.4 eV by diffuse reflectance and presented optimally efficiency on degradation of 10 ppm solution of AY17 (pH 4) at low bias potential (0.5 V) after only 30 min of experiment (Fig. 3). Therefore, the flower-like nanostructured Sn3O4 proved to be efficient in the visible light driven photoelectrocatalytic degradation of AY17 dye, which represents an energy-saving option for its future treatment and removal of the environment.