On the theory of mechano-catalytic water-splitting system

A theory has been developed for the mechano-catalytic water-splitting, which is the system of simultaneous H2 and O2 evolution by stirring the powder of an oxide semiconductor in pure water under the condition that the stirring rod must be kept in contact with the surface of the glass vessel. The kinetic equations and the coupling strength of the frictional energy conversion between mechanical and electrical systems are calculated. The total system composed of the formation of the dangling bonds on the glass surface, the trapping of the semiconductor particles at the microcrevice of the glass surface, the strong field inside the fine particles due to the frictional electricity, the mechanism of charge transfer from the semiconductor to the stirring rod, the hopping conduction of positive hole, the electric current density injected into water from the semiconductors, and the tunnel chemical reaction for splitting-water have been analysed. Some parts of this theory still remain at the phenomenological stage. Possibilities other than the frictional cause are also discussed.