Patent ID: 7615512

Claim:
A method, comprising: a) combining titanium compound particles with a carbon containing material to form a mixture, wherein the titanium compound particles each have a surface, and wherein the titanium compound particles have a specific surface area of at least 50 m 2 /g according to BET; then b) treating the mixture thermally for a time and a temperature sufficient to cause a reaction between the carbon containing material and the surface of the titanium compound particles to produce a photocatalytic surface layer of carbon doped TiO 2 , wherein the photocatalytic surface layer is activated by light of wavelength λ>400 nm, and wherein the resulting titanium dioxide particles having the photocatalytic surface layer of carbon display significant light absorption in the wavelength region λ>400 compared to pure titanium dioxide, and wherein the titanium dioxide particles contain 0.05-4 wt. % C referred to TiO 2 .