A study on the origin of nonfaradaic behavior of anodic contact glow discharge electrolysis: The relationship between power dissipated in glow discharges and nonfaradaic yields

Abstract

Chemical effects of contact glow discharge electrolysis (CGDE) at an electrode where a plasma is sustained by dc glow discharges between the electrode and the surrounding electrolyte, are remarkably nonfaradaic. A critical analysis of the chemical results of anodic CGDE at varying voltages, currents, power supplies, and pHs clearly shows that nonfaradaic yields originate in two separate reaction zones: the plasma around the anode and the liquid anolyte near the plasma-anolyte interface. The yields from the former zone appear from 250 V onward (the beginning of the onset of partial glow discharge) and vary linearly with the power dissipated in the glow discharge. The yields from the latter zone appear from 410 V onward (the beginning of the full glow discharge) and are independent of the power dissipated in the glow discharge. The relative contribution of the two zones to the total nonfaradaic yields is dependent on the voltage applied: the plasma zone having a share of 100% up to 400 V, followed by 20% up to 450 V, and thereafter rising steadily to 57% at 500 V.