Microwave plasma synthesis of TiO2 photocatalytic nanopowders

Chau Lik Hang
Industrial Technology Research Institute

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     Last modified: February 21, 2006

Abstract
Microwave Plasma Synthesis of TiO2 Photocatalytic Nanopowders

Joseph Lik Hang Chau
Ultrafine Powders Laboratory,
Industrial Technology Research Institute, Hsinchu, Taiwan



Abstract

Titania nanopowders were synthesized by using microwave plasma synthesis technique. The microwave plasma was operated in atmospheric pressure at a frequency of 2.45 GHz. The precursor material was put into the feed dosing device. The feeding rate of the precursor materials can be well controlled by the up-moving rate of the piston in the feeding device. Cooling gas was used to quench the as-synthesized particles in order to inhibit further particle growth and minimize coagulation. The precursor is decomposed thermally in the plasma reaction region and the products will then condensed in the heat exchanger which separate from the gas by the powder filter, and then finally collected in the powder collector. The effect of various processing parameters such as the effect of plasma gas and feeding rate was systematically studied in this work. TiO2 nanopowders were successfully synthesized by using the microwave plasma synthesis method. Manipulating the synthesis parameters such as the flow rate of plasma gas, cooling gas and feeding rate of precursor material can be used to control the average particle size and crystal phase of TiO2 nanopowders. This method is clean, direct, convenient and simple without the need of further purification of the product powders. The reaction processing time can also be significantly reduced comparing to wet-chemical methods.