High performance visible light responsive photocatalysts for environmental cleanup via solution processing

Fabrication of nitrogen-doped titania and/or strontium titanate nanoparticles via soft chemical reactions and their performance for environmental cleanup under visible light irradiation were introduced. Nitrogen-doped anatase, brookite and rutile with high specific surface area can be selectively prepared by the solvothermal reactions in mixed aqueous solution of titanium trichloride-hexamethylenetetramine. Nitrogen-doped strontium titanate can be prepared by mechanochemical reaction of strontium carbonate, titania and hexamethylenetetramine using a planetary ball-mill. Nitrogen-doped titania shows excellent photocatalytic activity for the nitrogen monoxide destruction under visible light irradiation. The photocatalytic activity of nitrogen-doped titania is in the order anatase > brookite > rutile. The photocatalytic activity of nitrogen-doped titania and strontium titanate can be improved by co-doping with higher valence metal ions to reduce oxygen vacancy and/or coupling with Fe2O3 and Pt to retard quick recombination of photo-induced electron and hole by the heterogeneous electron transfer.