Effects of pure and mixed stabilizers on opto-electrical properties and morphology of TiO2 nanoparticles synthesized by sol-gel method

Abstract

Titanium dioxide (TiO2) is acknowledged as the most advanced nanomaterial. It has been used in certain application, such as semiconductor, photocatalyst, dye solar cells, paints, dyes, cosmetics, antifogging coatings, self-cleaning windows, etc. Although TiO2 nanoparticles occur naturally in mineral form, but the particles are also being synthesized through different well-known techniques. The past literature reveals that sol-gel methodology is considered as the most attractive and suitable technique for the preparation of such kind of nanoparticles. This article reports the effects of three different stabilizers (HCl, HNO3 and mixture of HCl+HNO3) on the morphological and opto-electrical properties of TiO2 nanoparticles. The nanoparticles of TiO2 were synthesized through sol-gel process by using titanium tetra isopropoxide (TTIP) as precursor in a solution of deionized water and isopropanol at 80 °C under constant stirring. The synthesized TiO2 nanoparticles were characterized through X-ray Diffractometry (XRD), Scanning electron microscopy (SEM) and UV-Visible spectrophotometry. The grain size with perfect crystallinity obtained through XRD were in good agreement with SEM results. The grain size of the prepared TiO2 nanoparticles using HCl, HNO3 and (HCl+HNO3) were 3 nm, 2.8 nm and 3.3 nm, respectively. The optical characterization of TiO2 revealed band gap energy values of 4.10 eV, 6.16 eV and 6.14 eV corresponding to absorption edges at 302 nm, 201.2 nm and 201.73 nm, respectively. The smaller grain sizes were having larger band gaps.