CuMnO2, a novel hydrogen photoevolution catalyst

Photocatalytic hydrogen production induced under illumination using a new oxide CuMnO2 has been studied. The applied catalyst was without noble metal. The hydrogen was generated from aqueous solution containing either S2- or SO32-. The conduction band of CuMnO2, with a value of -0.88 V/SCE, allows a spontaneous hydrogen formation. The highest hydrogen evolution rate was 0.95 x 10(-2) ml mg(-1) h(-1) on the crednerite CuMnO2-E obtained by exchange reaction with SO32- as hole scavenger. When S-3(2-) was used, the hydrogen production reaches a saturation attributed to the competitive reduction of yellow S-3(2-) polysulfides S-n(2-) as well as their strong light absorption in the visible region. There was no photoactivity observed below pH 12. (C) 2002 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.