Enzyme-assisted synthesis of titania under ambient conditions

Abstract

A low-temperature procedure for the synthesis of TiO2 was developed using a water-soluble titanium complex and enzymes. Titanium-lactate and titanium-glycolate complexes were used as precursors of TiO2. Digestive enzymes were chosen as biocatalysts for the synthesis of TiO 2 in aqueous solutions. TiO2 powders were deposited from reaction solutions having optimal pH values for the enzymes to exhibit their catalytic activities for their original substrates. TiO2 has been synthesized by an enzymatic reaction in an aqueous solution under ambient conditions. The XRD measurements indicated that TiO2 powders thus obtained usually have an amorphous phase. However, after calcination at 550°C, the anatase phase was confirmed. Interestingly, the minor phase of TiO2, brookite, was found in the sample obtained from the titanium-glycolate complex catalyzed by lipase at pH 10 after calcination at 550°C. © 2008 The American Ceramic Society.