Glassy carbon electrode modified with blast furnace slag for electrochemical investigation of Cu2+ and Pb2+ metal ions

Abstract

The present work aims with electrochemical determination of non-biodegradable lead and copper metal ions using glassy carbon electrode (GCE) modified with pristine blast furnace slag (BFS). The GCE-BFS composite electrode was synthesized via the typical glassy carbon pastes with subsequent electrochemical characterization by voltammetric methods. Morphological studies were performed by scanning electron microscope (SEM) equipped with EDX elemental mapping. Surface area of the modified glassy carbon electrode was determined using the K3[Fe(CN)6] base solutions. In order to precisely determine the sensitivity, range of detection etc., significant operational parameters, which includes deposition time; potential, wave amplitude, and wave-frequency were finalized for the detection of Cd2+ and Pb2+. From the cyclic voltammetry results, the electrochemical behavior of the as-prepared GCE-BFS based modified electrodes was found to be irreversible in nature, and electron transfer was controlled by both the diffusion and adsorption process. Differential pulse voltammetry method was used for the quantitative determination of lead and copper. The results show two anodic peaks for lead ion due to ionic characteristic of blast furnace modified electrode. The limits of detection and quantification were found to be 0.084 μM, 0.281 μM for Pb2+ and 0.44 μM, 1.47 μM for Cu2+ ions, respectively. The BFS-GCE exhibit good sensitivity for Pb2+ 30.16 μA∙μM−1Cm−2 and 20.96 μA∙μM−1Cm−2 for Cu2+ respectively, with regression coefficient of 0.99.The superior sensitivity of these modified composite electrodes towards lead and copper ions has largely been attributed to its enhanced surface area, electronic conductivity, and enhanced electron transport rate which eventually results in better catalytic response of the target species.