Effect of gold oxide incorporation on electrochemical corrosion resistance of diamond-like carbon

• Au-DLC films presented superior impedance values as compared to DLC films.
• The corrosion potential shifts for less negative values when Au nanoparticles are incorporated in DLC structure.
• Gold nanoparticles prevent aggressive ions from attacking the substrate and thereby improve the corrosion resistance..

Gold oxide nanoparticles were incorporated into diamond-like carbon (DLC) films in order to improve protection of AISI-1020 from electrochemical corrosion. The AuOx:DLC films were prepared by plasma enhanced chemical vapor deposition and were subsequently characterized by scanning electron microscopy, Raman spectroscopy and electrochemistry measurements. The electrochemical corrosion performance of the AuOx:DLC coating was contrasted to AISI-1020 and DLC without AuOx coating. The electrochemical techniques that were utilized for this investigation were potentiodynamic and electrochemistry impedance spectroscopy. The electrochemical analysis indicated that AuOx:DLC films presented superior corrosion resistance as compared to DLC. This resulted in 99.8% and 96.8% protection efficiency respectively, when compared to AuOx:DLC and DLC coatings.

The corrosion potential shifts positively when Au nanoparticles are presented in DLC structure, which is consistent with improved corrosion protection. The reduction in anodic current by four orders of magnitude is consistent with a reduced rate of corrosion. Gold nanoparticles possibly decrease the porosity, increase the barrier properties and increase sp3 C, which improve the corrosion resistance of DLC film.Figure optionsDownload as PowerPoint slide