New cobalt(II)-based electrocatalyst for reduction of trichloroacetic acid and bromate

Abstract

A novel cobalt(II) complex trans-[Co(C6H11N3)4(SCN)2] (C6H11N3 = 1-butyl-1H-1,2,4-triazole) was synthesized and characterized by X-ray crystallography, IR spectroscopy and elemental analysis. The cobalt center is six-coordinate, CoIIN6, the axial positions being occupied by the isothiocyanate ligands and the equatorial positions by the 1-butyl-1H-1,2,4-triazole ligands. A conductive carbon paste electrode (Co-CPE), comprised of the studied complex and a carbon powder, was fabricated by the direct mixing method. The electrochemical behavior and electrocatalytic performance of Co-CPE were studied by cyclic voltammetry. The Co-CPE shows electrocatalytic activities toward the reduction of trichloroacetic acid and bromate. The detection limit and sensitivity are 0.01 μmol dm–3 and 76.86 μA μmol–1 dm3 for trichloroacetic acid, and 0.02 μmol dm–3 and 96.19 μA μmol–1 dm3 for bromate, respectively. The modified electrode features good reproducibility, high stability, low detection limit, technical simplicity and rapid preparation, which is important for practical applications.