Modification of nickel slag nanomaterials as a smart modifier of carbon paste electrodes in voltammetry-based lead pollutant detection

Abstract

Modification of nickel slag (NS) into a smart modifier carbon paste electrode (CPE) and its application test on lead (Pb) detection by voltammetry has been successfully investigated. The modification stage begins with the preparation of NS through the crushing process. The NS powder was put into the Hydrothermal Autoclave Reactor, heated at 180 °C for 2 h, calcined at 600 °C, and incorporated into the carbon paste electrode (NS/CPE) through mass variation. SEM and XRD characterization results illustrate that NS has a morphology composed of solid particles of varying sizes. Modification at 600 °C causes changes in morphology and an average diameter of 27.77 nm. Testing of the electrochemical behavior of NS/CPE on the Fe(CN)63−/Fe(CN)64− solution system described superior behavior marked by Ipa and Ipc values of 1.13x10−5 and −1.36x10−5 A/cm2, respectively. This value is generated from the NS/CPE application with a mass composition (w/w) of 2:5. Another superior behavior was demonstrated by the detection of reversible Pb (II) with Epa and Epc values of −0.10 V and −0.24, respectively. NS/CPE has good sensitivity with LOD and LOQ values of 0.889 μM and 2.96 μM, respectively. In addition, repeatability and reproducibility tests show that NS/CPE has good precision with a %RSD of 4.02% and 5.15%. The results of this work illustrate the potential for NS to be studied further as a new modifier material in the further development of voltammetry-based Pb (II) detection systems in the future.