Synthesis of Nitrogen-doped Titania by Solvothermal Reactions in Alcohols

Nitrogen-doped titania nanoparticles were obtained by the homogeneous precipitation in hexamethylenetetramine– titanium trichloride–alcohol aqueous solutions at 90℃ followed by heating at 190℃. Anatase,rutile and brookite were obtained,where the crystallite size,specific surface area and color greatly changed as 5～50 nm,20～200 m2/g and light gray to yellow,depending on the solvent and pH. The products after calcination were yellow,indicating doping with nitrogen ion. All colored titania showed photocatalytic activity under visible light irradiation for the oxidative decomposition of nitrogen monoxide in air. Especially,the nanoparticles of anatase type nitrogen-doped titania obtained using methanol aqueous solution showed excellent photocatalytic activity.