Effects of ageing periods on compositions and sizes of titanium dioxide particles synthesized by sol-gel technique

摘要

Titanium dioxide has attracted worldwide attention due to its prominent photocatalytic activity. It is generally accepted that nanoparticulate titanium dioxide with pure anatase structure exhibits high reactivity. Sol-gel is a simple and cost-effective technique capable of synthesizing anatase-phase titanium dioxide with particle sizes in nanometer range. This research aimed at examining effects of ageing periods on compositions and sizes of titanium dioxide synthesized by sol-gel technique. Experimental results revealed that prolonged ageing period demoted formation of anatase phase. Pure anatase phase was observed at ageing period of 1 day, while both anatase and rutile phases were observed at ageing periods of 4 and 7 days. The results also indicated that particle sizes decreased as the ageing periods increased. Nanoparticulate titanium dioxides with average sizes of 71.5, 50.4, and 29.7 nanometer were observed at ageing periods of 1, 4, and 7 days, respectively.