Studies on the structural, morphological and optical properties of HCl assisted vanadium oxide/tin oxide nanocomposites prepared by sol-gel method

Abstract Nanocomposites have gained much importance in different fields, commercially and technologically, due to the possibilities in tuning the properties of nanocomposites. In the present work, vanadium oxide (V2O5)/tin oxide (SnO2) nanocomposites were synthesized using simple sol-gel method. Two independent experiments were carried out to synthesis the V2O5/SnO2 nanocomposites. The V2O5/SnO2 nanocomposites were prepared from the precursors of tin chloride, ammonium metavanadate and ethanol (Experiment 1). A few ml of concentrated hydrochloric acid (HCl) was added in the precursors with and V2O5/SnO2 nanocomposites were prepared (Experiment 2) using ethanol as a solvent. Effect of HCl on the modifications of structural, morphological and optical properties of the V2O5/SnO2 nanocomposites was studied. Coexistence of V2O5 and SnO2 phases was confirmed by the X-ray diffraction studies. Thermogravimetric analysis (TGA) shows the stability of the as-synthesized V2O5/SnO2 nanocomposites from 350 °C. The crystallinity and the surface morphology of the synthesized V2O5/SnO2 nanocomposites were improved effectively due to addition of HCl in the preparation of the precursor solution. UV-DRS absorption spectra showed that the absorbance is modified and the band gap is decreased with increase in crystallite size due to the addition of HCl. The predominant Raman peaks at 140 cm−1 and 991 cm−1 confirm the presence of orthorhombic V2O5 phase. Further, the addition of HCl in the preparation of precursor solution revealed marked difference in the surface morphology of the nanocomposites.