Nano-crystalline titanium dioxide formed by reactive plasma synthesis

Nano-crystalline titanium dioxide finds extensive applications in photocatalytic degradation of harmful organic compounds pollutants in air and water. Synthesis and characterization of nano-crystalline TiO2 powder by reactive thermal plasma synthesis is presented here. Processing was carried out in a plasma reactor designed and developed in our laboratory. TiH2 powder was used as the precursor, which was injected into the thermal plasma jet along with air as the reactive gas. TiH2 particles, as they traverse the plasma jet, react with oxygen to form nano-sized TiO2 powder. Nano-sized TiO2 was also synthesized using Ti powder as the precursor. X-ray diffraction results showed complete conversion of the precursor into oxide. More than 75% of TiO2 formed was present as anatase. TEM showed well-resolved nano-sized particles with more than 70% lying in the range of a few nanometer to 20 nm. The powder has been used to study photocatalytic degradation of dye. (c) 2006 Elsevier Ltd. All rights reserved.