A graphene-printed paper electrode for determination of H2O2 in municipal wastewater during the COVID-19 pandemic

Abstract

Recently, hydrogen peroxide (H₂O₂) has been used as a disinfectant in sanitizers for cleaning hands, and solid surfaces of hospitals, offices and homes to prevent the spread of the COVID-19 virus. The effluents from domestic, hospital and municipal waste should be monitored for their H₂O₂ content to avoid the entry of this toxic pollutant into the ecosystem. Therefore, we developed a low-cost graphene (Gr)-printed paper electrode for determination of H₂O₂ using cyclic voltammetry (CV). An office inkjet-printer and Gr nano-ink stabilized with ethyl cellulose (EC) were used for the fabrication of printed paper electrodes (PPEs) to determine H₂O₂ quantitatively. A stable Gr–EC nano-ink (2%) with viscosity and surface tension values of 12 mPa S⁻¹ and 35 mN M⁻¹, respectively, was formulated to obtain conductive electrodes. A wide linear range (2 μM–25 mM) with a better limit of detection (0.28 μM) for the determination of H₂O₂ was obtained when the Gr–EC/PPE was used as a working electrode. Further, the Gr–EC/PPE was successfully employed for analysis of H₂O₂ in wastewater. The electrochemical determination of H₂O₂ using the Gr–EC/PPE as an electrode in CV is rapid, economical, flexible and eco-friendly when compared with previously reported methods.