Tin-derivative sandwich-type polyoxometalates supported on Nd-doped TiO2 nanoparticles as efficient and reusable catalysts in the oxidation of sulfides and alcohols

New nanocomposites, including different loading levels of sandwich-type polyoxometalates [((HOSnOH)-O-IV)(3)(XW9O34)(2)](n-) (X = As (1), P (2) n = 12 and Si (3) n = 14) on Nd-doped TiO2 nanoparticles were prepared by a simple impregnation method. The nanocomposites were characterized by X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy, Fourier transform infrared (FTIR), and energy-dispersive X-ray spectroscopy. Compounds 1-3 were successfully loaded on Nd-doped crystallized anatase-phase TiO2 nanoparticles of 20-25 nm. Catalytic activities of nanocomposites were examined by carrying out the oxidation of sulfides and alcohols with H2O2. Simple synthesis method, reusability, and low amounts of the heterogeneous catalysts with a slight excess of H2O2 and mild reaction conditions make these oxidation reactions an environmentally benign chemical process.