Abstract. Carbon-coated Magneli phases TinO2n-1 were prepared by a simple heat treatment of the powder mixture of rutile-type TiO2 with poly(vinyl alcohol) PVA at 1100 oC in inert atmosphere. The lower TiO2/PVA ratio in the mixture resulted in TinO2n-1 with the lower n-value. Carbon-coated TinO2n1 phases thus prepared showed photocatalytic activity under visible light. The TinO2n-1 phas…