Chondroitin sulfate as a green corrosion inhibitor for zinc in 26% ammonium chloride solution: Electrochemical and surface morphological analysis
By Singh, Ambrish; Ansari, K. R.; Quraishi, M. A.
Published in Colloids and Surfaces A: Physicochemical and Engineering Aspects
Colloids and Surfaces A: Physicochemical and Engineering Aspects
2020
Abstract
In the present investigation, Chondroitin sulfate (CS) has been tested as green as a corrosion inhibitor for zinc-carbon battery by using electrochemical impedance spectroscopy (EIS), electrochemical frequency trend modulation (EFTM) and potentiodynamic polarization (PDP) measurements. The calculated results suggest that inhibition efficiency is 98.9% at the optimum concentration (200 mg/L) in 26% NH4Cl solution at 308 K. The outcome of EIS indicates that the values of double-layer thickness increased as the CS concentration increased. EFTM suggests in the presence of CS corrosion rate and corrosion current decreased.PDP results reveal that the nature of CS adsorption is mixed with dominantly cathodic.CS adsorption on the zinc surface obeyed the El-Awady adsorption isotherm model. The magnitude of ?Gads supports the chemical nature of CS adsorption. The Scanning electron microscope (SEM), Energy dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS) study supports the presence of CS adsorbed film over the zinc surface.