Engineering low-cost and efficient materials for sensing hydrazine (HA) is critical given the adverse effects of high concentrations on humans. We report an efficient electrode made up of rod-shaped Co3O4/g-C3N4 (Co3O4/graphitic carbon nitride (GCN))-coated fluorine-doped tin oxide as a desirable electrode for the detection of HA. GCN is synthesized by the thermal decomposition of melamine, Co3O4, and the heterostructure is grown by a hydrothermal process. The as-prepared materials were characterized by using spectroscopic and microscopic techniques. The voltammetric studies showed that HA can be oxidized at a lower onset potential of 0.24 V vs reference Ag/AgCl, and the composite yielded a significantly enhanced oxidation peak current than the pure components because of the high electrocatalytic activity and the synergy between Co3O4 and GCN. By employing chronoamperometry, the proposed sensor can detect HA in a wide range with a high sensitivity of 819.52 μA mM-1 cm-2 and a detection limit of 3.14 μM. The high conductivity of Co3O4, enhanced electroactive surface area, the rich redox couples of Co2+/Co3+, and the additional catalytic sites from GCN are responsible for the high performance of the heterostructure.
Keywords: Co3O4; chronoamperometry; electrochemical sensor; graphitic carbon nitride; hydrazine; spinel metal oxide.