Environmentally friendly synthesis of Co-based zeolitic imidazolate framework and its application as H2O2 sensor

[Display omitted] •A facile and environmentally friendly method for synthesizing Co-based imidazolate framework compounds was provided.•The Co-based imidazolate framework compounds with five different morphologies were synthesized.•A novel H2O2 sensor was constructed. The work presented that by regulating the proportion between cobalt and 2-methylimidazole in distilled water, a series of Co-based imidazolate framework compounds with diverse shapes were synthesized at ambient temperature. The morphology and structural characteristics of the compounds were surveyed by scanning electron microscope, energy disperse spectra, powder X-ray diffraction and N2 absorption-desorption. It was found by cyclic voltammetry that the zeolitic imidazolate framework compound synthesized at a ratio of 1:20 had the best electrocatalytic activity to H2O2 reduction, therefore, the compound was chosen to fabricate a H2O2 electrochemical sensor. Electrochemical studies indicated that the sensor had a determination limit of 0.7 μM and short response time within 3 s. The catalytic current was linear with H2O2 concentration from 2.5 to 212.5, 212.5 to 1662.5 and 1662.5 to 6662.5 μM and the sensitivity were 12.2, 5.3 and 2.4 μA mM−1 cm−2, respectively. Furthermore, the proposed sensor showed a good anti-interference capacity, repeatability and stability.