Performance of tin doped titania hollow spheres as electrocatalysts for hydrogen and oxygen production in water electrolysis

The electrocatalytic activity of tin doped TiO2 hollow sphere particles has been examined in acid solution. Titania hollow spheres have been synthesized by using poly(styrene-methacrylic acid) latex particles as a template, and tin was doped over spheres with the appropriate amount of SnCl2·2H2O solution in HCl. The surface characteristics have been evaluated by XRD, SEM and TEM analysis. XRD analysis has shown the presence of rutile SnO2 and TiO2 phase in the catalysts; and the peak intensity for SnO2 phase increased with rise in the calcination temperature indicating the critical growth of tin on the surface of the catalysts. Diameter of pure TiO2 hollow spheres and Sn doped samples were found from SEM and TEM images in the range of 1–1.2 and 0.4–0.6 μm, respectively. TGA has been performed with the uncalcined 40 wt% Sn doped TiO2 catalyst. The peaks for hydrogen and oxygen production are present significantly for all the hollow sphere samples in cyclic voltammograms; but peaks for hydrogen production is more prominent in 20 and 40 wt% Sn/TiO2 catalysts. The performances of the hollow sphere electrocatalysts were evaluated up to current densities of 50 mA cm−2 during anodic polarization measurement. Sn/TiO2 electrocatalysts have also shown long time electrochemical stability in acidic media.