Neutral, stable and transparent photocatalytic titanium dioxide sols

摘要

Disclosed is a method for preparing a pH neutral titanium dioxide sol comprising (1) contacting a hydrous titanium dioxide gel with an alkaline peptizing agent (e.g., diethyl amine) to provide a peptized alkaline titanium dioxide sol; (2) neutralizing the peptized alkaline titanium dioxide sol with an acid (e.g., a mixture of phosphoric and acetic acid); and (3) obtaining or collecting the neutral, stable and transparent photocatalytic titanium dioxide sol. The titanium dioxide sol is stable and transparent over a range of pH of about 7.0 to about 9.5. The titanium dioxide sol may include crystallites of titanium dioxide having an average particle size of less than about 10 nm with at least 90% of the crystallites being in the anatase form.