SYNTHESIS AND CHARACTERIZATION OF TIO2 NANOPARTICLES AND ITS BAND GAP ENERGY ESTIMATION

Abstract

Nanocrystalline semiconductor metal oxides have achieved a great importance in our industrial world today. They may be defined as metal oxides with crystal size between 1 and 100 nm. TiO2 nanosized particles have attracted significant interest of materials scientists and physicists due to their special properties and have attained a great importance in several technological applications such as photocatalysis, sensors, solar cells and memory devices. The objective of the project is to undertake synthesis and characterization of TiO2 nanoparticles and its band gap estimation. In this paper TiO2 nanoparticles were synthesized by sol-gel method using TiCl4 solution added in deionized water in ice bath under fume hood followed by the addition of ethanol with vigorous stirring for 30 min at room temperature. A drop wise of ammonium hydroxide (NH4OH) was added and stirred vigorously, then settled for 12 hrs and washed with distilled water. The gel solution was obtained and then got dried using oven at 200oC for 4 hours. Then, the dried gel was calcined at 4000C using furnace for 2 hours. Finally, TiO2 nanopowder was obtained. The characterization of particles was carried out by SEM and UV-Vis spectroscope techniques. Spongy like shape and small size of the sample was detected from diameter indicated by SEM image and UV-vis spectroscopy, which shows the wavelength of the synthesized nanoparticle at maximum absorbance is equal to ~376nm. Then the energy band gap of the synthesis nanoparticle TiO2 was estimated from this value of wavelength and is equal to~3.3ev.