Synthesis, characterization and performance of two new Co(II) complexes as electrocatalyst of hydrogen peroxide and trichloroacetic acid

Two new complexes of [Co(C4H9-bim)2Cl2] (1) and [Co(C4H9-bim)2(SCN)2] (2) (bim = benzimidazole) were synthesized and the structures were characterized by X-ray crystallography, IR spectroscopy and elemental analysis. The cobalt atoms of the two complexes both adopt distorted tetrahedral geometry. Two new cobalt complexes were used as bulk modifier to fabricate two carbon paste electrodes (Co-CPE: 1-CPE and 2-CPE). The electrochemical behaviors of two modified electrodes were characterized by cyclic voltammetry. They have similar electrochemical behaviors and good electrocatalytic activities toward the reduction of hydrogen peroxide and trichloroacetic acid (TCA). Two modified electrodes have good reproducibility, high stability, low detection limit, technical simplicity and possibility of rapid preparation, which is important for practical application.