Electrochemical behavior of nitrogen gas species adsorbed onto boron-doped diamond (BDD) electrodes

The adsorption of nitrogen species, in neutral electrolyte solutions, onto boron-doped diamond (BDD) electrode surfaces from dissolved NO₂, NO, and N₂O gases was induced at 0 V/SCE. Modified BDD electrode surfaces showed a different electrochemical response toward the hydrogen evolution reaction than did a nonmodified electrode surface in electrolyte base solution. The formation of molecular hydrogen and nitrogen gaseous species was confirmed by the online differential electrochemical mass spectrometry (DEMS) technique. Among the three nitrogen oxides gases, NO₂ substantially modifies the electrolyte via hydrolysis leading to the formation of NO₃ ^- and its adsorption on the BDD electrode surface. The BDD/(NO ₃^-) interface was the only N₂O and N ₂ species generating system.