Hydrothermally modified PVA/ZnS-NCQD nanocoating for stainless steel corrosion protection in saline water

Abstract

Herein, we report a facile method for the fabrication of a hydrothermally modified well shaped nanocubed ZnS quantum dot (NCQD)/polyvinyl alcohol nanocomposite. The prepared nanocomposite via this method was characterized using various techniques such as field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and atomic force microscopy (AFM). For the first time, a thin film of the fabricated nanocomposite was coated on 316L stainless steel alloy by heat treatment. The corrosion protection efficiency of the PVA/ZnS-NCQD nanocomposite coating on stainless steel was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques in 3.5% NaCl solution. The corrosion protection of stainless steel was enhanced in the presence of the PVA/ZnS-NCQD nanocomposite coating which exhibited better corrosion resistance in saline water. The presence of ZnS-NCQDs increases the inhibition efficiency of PVA against the corrosion of stainless steel in chloride solution from 67.0% to 94.0%. The electrochemical corrosion parameters obtained from potentiodynamic polarization and EIS are in good agreement.