Development of environment-friendly reduced graphene oxide coating and corrosion behaviour on cold-rolled interstitial-free (IF) steel

Many different processes have been developed to grow graphene film to protect metals. These processes are primarily based on chemical vapour deposition and are challenging to scale. In this paper, we have attempted to grow the reduced graphene oxide (rGO)-like film using the natural resin ‘shellac’ as a precursor through the simple process of dip coating of shellac varnish and annealing of coated substrates in a reducing atmosphere. X-ray diffraction (XRD) analysis and Raman spectroscopy were used to establish the rGO phases grown in the coating. The corrosion studies of rGO films grown on cold-rolled interstitial-free steel are investigated with different loadings of shellac in the varnish solution and subsequent heat treatments. Scanning electron probe micro-analysis was done to do elemental analysis, and potentiometric studies were done to investigate the corrosion behaviour of the coatings. The structure–property correlation of the film has established the corrosion mechanism using different microscopy techniques.