The present invention is directed to a process for the manufacture of iron oxide particles coated with crystalline titanium dioxide, wherein the process comprises the steps of adding an aqueous solution of at least one titanyl salt to an iron oxide dispersion to form a reaction mixture, precipitating titanium dioxide on said iron oxide particles by adding an alkali, wherein the titanium dioxide is at least partially in a crystalline form, and isolating the resulting titanium dioxide-containing iron oxide particles from the reaction mixture. The invention is further related to iron oxide particles comprising precipitated crystalline titanium dioxide and the use of the resulting photocatalitycally active material.