The invention relates to a titanium dioxide-based photocatalyst containing carbon that is highly photoactive in visible light (vlp-TiO.sub.2) and to a method of manufacture. The vlp-TiO.sub.2 is manufactured by mixing a fine grained titanium compount (BET.gtoreq.50 m.sup.2/g) with an organic carbon compound and subsequent thermal treatment at temperatures up to 350.degree. C. The carbon content amounts to 0.05 to 4% by weight, preferably 0.4 to 0.8% by weight. The product is characterized by an ESR spectrum which displays only one significant signal in the g value range from 1.97 to 2.05 at g about 2.003. The inventive photocatalyst can be used for to degrade contaminants and pollutants in liquids and gases.