Effect of nitrogen configuration on carbon nanowall surface: Towards the improvement of electrochemical transduction properties and the stabilization of gold nanoparticles

Abstract In this work, unintentionally nitrogen doped carbon nanowall (CNW) films, deposited on silicon substrates, were treated in argon plasma admixed with nitrogen (Ar/N 2 ) or oxygen (Ar/O 2 ). X-ray photoelectron spectroscopy (XPS) showed that oxygen functional groups have been incorporated in various amounts with high nitrogen doping concentration (∼12.5–13.5 at%. for Ar/N 2 and Ar/O 2 gas mixtures). More importantly, nitrogen configuration on the surface has been modified after the treatment. The electrochemical reactivity of the CNW electrodes, before and after the treatment, was investigated by both cyclic voltammetry (CV) and electrochemical impedance spectroscopy. The CV results indicate that the pyrrolic nitrogen can play a key role in the electrochemical transaction improvement. In addition, deposition of gold (Au) nanoparticles (NPs) onto CNW samples and their interaction with CNWs has been discussed through XPS results. It was suggested that a certain nitrogen configuration there is a promotion of electron donation from nitrogen to the Au NPs. Such findings open the way to design nitrogen doped carbon materials with specific nitrogen configuration to improve electrochemical properties and to prepare better platform for Au NPs for use in catalysis and sensor applications.