Nanocrystalline $TiO_2$ by three different synthetic approaches: A comparison

Abstract

A comparison of the efficiency of three different synthetic routes viz. sol–gel method involving templating, mechanochemical synthesis and combustion synthesis for the production of nanostructured $TiO_2$, is reported. In the sol–gel method, nanocrystalline $TiO_2$ is produced when titanium tetraisopropoxide is templated onto dodecylamine which forms the liquid crystalline hexagonal structure and the template is then extracted using 1 : 1 solution of ethanol–hydrochloric acid mixture. Mechanochemical synthesis of nanocrystalline $TiO_2$ involved mechanical illing of stoichiometric amounts of titanium and cupric oxide in a planetary ball mill using stainless steel vial with wear resistant stainless steel balls. Nanocrystalline $TiO_2$ is produced by the combustion reaction involving titanyl nitrate and fuels like glycine and citric acid. Nanostructured $TiO_2$ with an average particle size of $\sim 14 nm$ is produced by the sol–gel method whereas the mechanochemical reaction between titanium and cupric oxide resulted in the formation of nanocrystalline $TiO_2$ with an average particle size of $\sim 20 nm$ after 12 h of milling. On the other hand, combustion synthesis resulted in the formation of nanocrystalline $TiO_2$ with an average particle size of less than $\sim 50 nm$. The microstructures of nanocrystalline $TiO_2$ produced by the above three methods are analysed