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 SO2−3 . 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 × 10−2 ml mg−1 h−1 on the crednerite CuMnO2-E obtained by exchange reaction with SO2−3 as hole scavenger. When S2− was used, the hydrogen production reaches a saturation attributed to the competitive reduction of yellow polysulfides Sn2− as well as their strong light absorption in the visible region. There was no photoactivity observed below pH 12.