Exploration of MnO2/carbon composites and their application to simultaneous electroanalytical determination of Pb(II) and Cd(II)

We report preparation of MnO2 composites with carbon (Vulcan, graphite, and carbonized nanostructured polyaniline 5-sulfosalicylate) via hydrothermal and low-temperature wet impregnation procedure. All prepared composites were characterized using thermogravimetric analysis, X-ray diffraction, scanning electron microscopy and conductivity measurements, and their characteristics compared. Furthermore, novel micro/nanostructured manganese dioxide/carbon composite based electrodes were tested for simultaneous determination of Pb2+ and Cd2+ as model analytes by anodic stripping voltammetry. The oxidation of the targeted heavy metals at the investigated composite electrodes gave distinctive and well separated peaks with lowest detection limits of 27 nM for Pb2+ and 52 nM for Cd2+ ions obtained with hydrothermally prepared MnO2/graphite composite based electrode.