In-situ reduced graphene oxide-polyvinyl alcohol composite coatings asprotective layers on magnesium substrates

A simple and feasible method was developed to fabricate in-situ reduced graphene oxide-polyvinyl alcoholcomposite (GO-PVA) coatings as protective layers on magnesium substrates. Polyvinyl alcohol was used as anin-situ reductant to transform GO into reduced GO. Contiguous and uniform GO-PVA coatings were preparedon magnesium substrates by dip-coating method, and were further thermally treated at 120 °C under ambientcondition to obtain in-situ reduced GO-PVA coatings. Owing to the reducing effect of PVA, thermal treatment atlow temperature led to effective in-situ reduction of GO as confirmed by XRD, Raman, FTIR and XPS tests. Thecorrosion current density of magnesium substrates in 3.5 wt% NaCl solution could be lowered to its 1/25 whenusing in-situ reduced GO-PVA coatings as protective layers.