Electrical breakdown of water using porous ceramic-coated electrode

Electrical breakdown of water using porous ceramic-coated rod electrodes were investigated for two types of ceramics, oxide (corundum) and silicates (almandine). Properties of the ceramic layer and its interaction with the electrolyte, i.e., surface chemistry at the electrolyte/ceramic surface interface, were found as important factors in generating electrical discharges in water. The buildup of surface charge, which was determined by the polarity of the applied voltage, pH and chemical composition of aqueous solution, led to the formation of an electrical double layer at the ceramic surface. Under an externally applied electric field, this double layer becomes polarized, which affected the electric field distribution on the ceramic electrode and conditions needed for initiation of the discharge in water.