A Study in Atmosphere Dielectric Barrier Discharge Plasma Electrode Catalytic Effect Using Oxygen and Nitrogen

Atmospheric dielectric barrier discharge (DBD) plasma creates a gaseous environment conducive to the generation of reactive species. DBD plasmas have a variety of applications in the clinical and industrial fields. During this experiment, an DBD plasma was ignited in controlled gas environments using alumina as a dielectric barrier with gold, copper, or nickel electrodes. The gas environment was formed by varying ratios of oxygen, O2, and nitrogen, N2, with trace amounts of water and carbon dioxide. The plasma transformed these diatomic molecules into reactive species, primarily ozone, O3, and nitric acid, HNO3. A higher initial percentage of oxygen will result in a higher ozone concentration. The selected electrode material also alters the concentrations of ozone and nitric acid. Additionally, the electrode material can modulate the ratio of ozone to nitric acid, providing a specific selectivity between reactive species. The electrode material generating the highest ozone concentration was gold, then copper and nickel. The electrode material with the highest ratio of ozone to nitric acid was nickel at 4:1; then gold at 2:1; and copper at 1.5:1. Utilizing these parameters allows for the generation of reactive species to desired concentrations and specific selectivity.