Corrosion inhibition studies of cigarette waste on the iron surface in acid medium: electrochemical and surface morphology analysis

Abstract

Purpose – The purpose of this paper is to study the corrosion inhibition tendency of cigarette waste (water extracts of cigarette butts, WECB) on an iron surface in an acid medium. Design/methodology/approach – The electrochemical impedance spectroscopy and polarization techniques were used to analyze the performance of WECB on the iron working electrode. Electrochemical polarization curves were used to determine the intensity of the metal corrosion, specifically to see the effectiveness of the anodic and cathodic reactions in the corrosive medium having WECB. Moreover, the electrochemical impedance of WECB with electrode was analyzed qualitatively. The electrochemical data that relate isotherm adsorption of WECB with iron were analyzed; furthermore, the scanning electron microscope was used to analyze morphology change during the corrosion inhibition. Findings – After analyzing the impedance data, it is seen that there exists a single capacitive semicircle at the higher frequency range corresponding to a one-time constant in the Bode-phase plot. In the polarization curves studies (Tafel slopes), the current densities of both cathodic and anodic branches are greatly affected in the presence of WECB in the corrosive medium, suggesting that WECB performs as a mixed inhibitor. The free energy data and Temkin adsorption isotherm process show that the adsorption process of WECB on the metal surface follows a physisorption. Furthermore, the WECB-coated metal surface analyzed by scanning electron microscopy confirms the corrosion inhibition of WECB in the acid medium. Research limitations/implications – An in-depth characterization of the corroded scales is recommended to endorse the results of this study. Social implications – There may be some people who may challenge that the research may encourage smoking; however, if taken positively, the research offers a very cost-effective and eco-friendly solution to tackle the cigarette waste. Originality/value – Idea of the present work is to reuse the WECB as corrosion inhibitors for the metal surface, as this waste contains large amount of nicotine, which exhibits corrosion inhibition properties. The present work deals with the study of corrosion inhibition properties of WECB on the iron surface in acid medium. The findings of this study can be very useful from scientific, as well as industrial application point of view. Moreover, the research is important as there is no proper recycling process for this waste so as to maintain a clean environment.