Development of in-situ electrochemical heavy metal ion sensor using integrated 1D/0D/1D hybrid by MWCNT and CQDs supported MnO2 nanomaterial

Abstract

An integrated 1D/0D/1D hybrid nanomaterial was prepared from MWCNT supported carbon quantum dots @ MnO₂ nanomaterial for a sensitive and selective electrochemical heavy metal ion sensor by hydrothermal methods. The developed nanomaterials were characterized by various analytical methods such as FESEM, HRTEM, XRD, FTIR, EDX and elemental mapping study, and also its electrochemical properties of the prepared samples were investigated by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analysis. Differential pulse voltammetry (DPV) analysis has been used to investigate the quantitative detection of heavy metal ions such as cadmium and chromium on modified electrodes under optimal conditions. The in-situ electrochemical sensitivity and selectivity of the samples were determined by varying various parameters, such as the concentration of heavy metal ions, different electrolytes and electrolyte pH. The observed DPV results show that prepared MWCNT (0.05 wt%) and CQD (0.1 wt%) supported MnO₂ nanoparticles show effective detection response for chromium (IV) metal ion. In particular, 0D CQD, 1D MWCNT, and MnO₂ hybrid nanostructures produced a synergistic effect among them, resulting in strong electrochemical performance of the prepared samples against the target metal ions.

Keywords: Cadmium; Carbon quantum dot; Chromium; Dimensional hybrid; Electrochemical sensor; MWCNT; MnO(2).