A Study of Mechano-Catalysts for Overall Water Splitting

Mechano-catalytic overall water splitting on Cu 2 O, NiO, and Co 3 O 4 was investigated in order to reveal the reaction mechanism. The experimental results indicated that metallic elements of these oxides were generated during the reaction. Also, elemental metals Cu, Ni, and Co were oxidized into Cu 2 O, NiO, and Co 3 O 4, respectively, when water was reduced into H 2 by the metal powders under the same reaction condition. The metallic particles covered with the metal oxides evolved both O 2 and H 2 . These results suggest that a redox reaction between the metal and metal oxide may be responsible for H 2 and O 2 formation of the mechano-catalytic overall water splitting.