Low temperature vapor-phase preparation of TiO2 nanopowders

摘要

The preparation of TiO2 nanopowders by vapor-phase hydrolysis of TiCl4 below 600℃is studied in this paper.Influences of preparation variables, such as preparativetemperature, residence time, reactant concentration, and H2O/TiCl4mole ratio, on TiO2 particle size, morphology and chlorinecontamination are investigated, followed by discussion. It showsthat the hydrolysis temperature exerts greatest influences, while theresidence time hardly have impact on product particles below 400℃, among the hydrolysis variables investigated. The chlorinecontamination on nanopowders occurs during the preparationwhich can be greatly reduced by proper control on preparationvariables. Unlike the high temperature gas-phase processes such asoxidation route and flame synthesis, low-temperatue route showsthe ready control on product powders , and thus obtains titaniapowders with small size , narrow size distribution and very weakagglomeration. In addition, the decreased energy consumption,retarded corrosion on the reactor and the reduced operationproblems would be expecte for the low temeprature processes.