The properties of CuFeO2 have been studied according to the catalytic hydrogen production upon visible light. CuFeO2 with a low band gap F, a good chemical stability and a suitable flat band potential appears as a suitable,candidate. The potential of photoelectrons allows favorably a thermodynamically H-2-evolution from alkaline thiosulfate S2O32- solution. There is a major difference between pure and loaded oxide with some metal catalysts. Our best results have been obtained with unloaded CuFeO2 at 50 degrees C and pH 13,60. Thiosulfate S2O32- ions can be oxidized to sulfite SO32- and subsequently to sulfate SO42- and the electronic exchange occurs via mediation of surface states. The quite high H-2-formation at the beginning shows a tendency towards saturation, it competes with SO32-, produced by parallel oxidation of S2O32- (c) 2004 Published by Elsevier Ltd.