A method for synthesising a nanometre-scale titanium dioxide gel

摘要

A method for synthesising a nanometre-scale titanium dioxide gel which comprises the steps of dissolving and diluting a titanium compound, adding ammonia water to produce a precipitate of titanium hydroxide or titanic acid. The precipitate is filtered and the filter cake re-suspended in deionised water and an oxidant or inorganic acid and a modifier and the suspension agitated at an elevated temperature to form a gel, and the pH of the gel is adjusted. The oxidant may be perchloric acid, periodic acid, potassium permanganate, sodium permanganate or nitric acid. The inorganic acid may be perchloric acid, periodic acid, nitric acid, phosphoric acid, hydrochloric acid, sulphuric acid, hydroiodic acid or hydrobromic acid. The modifier may be silicate, polyaluminium chloride, aluminium sulphate or silane. A surfactant may also be added.