Nanostructuring of SnO₂ via solution-based and hard template assisted method

Polycrystalline SnO₂ 1D nanostructures with diameters of 150–200 nm and consisting of uniformly sized single-crystallites of ~ 10 nm in size were produced via aqueous sol-gel and hard template assisted methods. Stable sols were prepared from tin oxalate precursor, citric acid and H₂O₂. Solution chemistry and parameters influencing the stability of the sol and morphological structure of the resulting materials are addressed. Morphological and structural characterization revealed uniform and porous structure of the nanostructured SnO₂. Hollow nanotubular structures were produced from solutions of lower concentration. Results of XPS analysis revealed that a sub-stoichiometric phase with surface composition of SnO_1.8 was obtained indicating the formation of oxygen vacancies. The optical properties were investigated and optical band gap energy for the powder samples was estimated to be 3.61 eV. An environmentally friendly aqueous sol-gel route developed to prepare homogeneous nanostructures of 1D SnO₂ will enable facile fabrication of various oxide based nanostructured materials.