Abstract
We report the successful formation of cobalt oxide (Co3O4) nanoparticles/multi-walled carbon nanotubes (Co3O4/MWCNTs) composites as efficient electrocatalytic materials for chemical sensing. Co3O4/MWCNTs composites were synthesized via a straightforward hydrothermal treatment and comprehensively characterized. Working as effective electron mediators, the prepared Co3O4/MWCNTs composites were used for the fabrication of hydrazine (N2H4) and glucose sensors. The electrochemical impedance spectroscopy (EIS) studies confirmed Co3O4/MWCNTs/glassy carbon electrode (GCE) exhibited higher conductivity than bare GCE and Co3O4/GCE, endorsing a faster electron transfer rate and a higher electrocatalytic activity. The addition of MWCNTs can not only improve the dispersion of Co3O4 nanoparticles but also facilitate the electron transfer rate. The sensitivity, selectivity, repeatability, reproducibility, linear range and detection limit of the fabricated sensors were systematically investigated. The fabricated hydrazine sensor displayed a great sensitivity of 120.26 mA mM(-1), a wide linear range of 1.0-187.4 mM, and a rather low detection limit of 0.449 mM, and the fabricated glucose sensor exhibited a high sensitivity of 63.27 mA mM(-1), a wide linear range of 1.70-554 mM, and a low detection limit of 0.95 mM. We demonstrated that such fabricated Co3O4/MWCNTs composites may have favorable applications in the establishment of fast and effective determination of environmental pollutants.