Effect of r-GO/TiO₂ hybrid composite as corrosion-protective coating on magnesium in sulphur-based electrolyte

Abstract

Purpose

This paper aims to examine the investigations made on the corrosion behaviour of magnesium (Mg) substrate electrodeposited using different nano-materials.

Design/methodology/approach

This study uses nano-materials such as those of reduced graphene oxide (r-GO), titanium-di-oxide (TiO₂) and also r-GO/TiO₂ nano-composites (dispersed through ultra-sonication process) at 3-min time interval. Crystalline nature of synthesized TiO₂ is studied through X-ray diffraction and its pore volume is measured to be approximately 0.1851ccg-1 by Brunauer Emmett Teller analysis.

Findings

Surface morphology of the developed set of specimens inspected through scanning electron microscopy and energy dispersive spectroscopy establishes a clean surface coating and further witnesses for only minimal defects. Electrochemical behaviour of the developed coating is studied exhaustively using Tafel polarization and electrochemical impedance spectroscopy in 0.1 M Na₂SO₄ solution.

Originality/value

Incremental corrosion resistance exhibited by developed composite coating owes to the factors viz. chemical stability and hydrophobic tendency of TiO₂ and r-GO; these known engineering facts resist the flow of ions into the corrosive media and thereby reduce the rate of corrosion.

Citation

Mohan Das Gandhi, A.G., Soorya Prakash, K. and Kavimani, V. (2018), "Effect of r-GO/TiO₂ hybrid composite as corrosion-protective coating on magnesium in sulphur-based electrolyte", Anti-Corrosion Methods and Materials, Vol. 65 No. 4, pp. 375-382. https://doi.org/10.1108/ACMM-09-2017-1837