effects of sol concentration on the structural and optical properties of sno2 nanoparticle

In this paper, the effects of changes in sol concentration on the structural and optical properties of sno2 nanoparticles are studied through the sol-gel method. sno2 nanoparticles are produced from different sno2 solution concentrations (0.1, 0.3 and 0.5 mol/l) at room temperature. x-ray diffraction (xrd) and scanning electron microscopy (sem) analysis are used to investigate the effects of changes in sol concentration on the crystalline and surface morphology of nanoparticles. the xrd pattern shows that the particles are in the standard tetragonal phase of sno2. the crystallites sizes are 11.7nm, 18.8nm, and 74.8nm, for 0.1 m, 0.3m and 0.5 m of concentration respectively. the average size of sno2 particles decreases by a reduction in the sol concentration. the band gap value is 4.07ev, 4.28ev and 4.36ev for 0.5m, 0.3m and 0.1m of concentration respectively. the uv-visible analysis shows that decreasing the sol concentration will cause the absorption edge shift to the shorter wavelengths, because decreasing the sol concentration will reduce the nanoparticles size, and smaller nanoparticles size absorb shorter wavelengths better and also increase the band gap.