Reduction and characterization of the band gap of TiO2 nanoparticles

Abstract

The increase of pollution in both air and water due to anthropogenic causes, especially in large cities, is a tendency that should be reverted. Many of these pollutants can be degraded through the absorption of solar energy by a photocatalyst. Titanium dioxide (TiO2) is a semiconductor that can act as a photocatalyst when absorbing light from the UV region of the spectrum (100-400 nm), which only represents 4-6% of sunlight. To make the most of the sun’s energy, and to be able to apply this process efficiently on a large scale, black TiO2, which can absorb practically the entire range of the solar spectrum, has been synthesized. In this work, TiO2 nanoparticles are synthesized by sol-gel method and different treatments are applied to obtain black TiO2. Finally, the products obtained are characterized by FESEM, Raman spectroscopy, XRD and Photoluminescence Spectroscopy, and compared to commercially available TiO2 nanoparticles. Moreover, the degradation of an organic molecule in presence of an aqueous suspension of TiO2 inside a solar simulator is studied to test out the photocatalytic efficiency of the products