Electrochemical behavior of nitrogenated nanocrystalline diamond electrodes

Nitrogenated nanocrystalline diamond films with controlled conductivity are deposited from microwave plasma in CH4-Ar-H-2-N-2 gas mixtures. They are characterized using atomic force microscopy, Raman spectroscopy, and electrophysical measurements. Their electrochemical properties are studied by cyclic voltammetry and electrochemical impedance spectroscopy. Kinetic parameters of reactions in [Fe(CN)(6)](3-/4) redox system are determined. The character of electrode behavior is controlled by the degree on nitrogenation. With the increasing of the nitrogen content in the reaction gas mixture (from 0 to 25%), the potential window somewhat narrows, the background current increases, the reversibility of reactions in the [Fe(CN)(6)](3-/4) redox system increases. By and large, the transition occurs from the electrochemical behavior of a "poor conductor" to that of a metal-like electrode.