Synthesis of porous nanododecahedron Co3O4/C and its application for nonenzymatic electrochemical detection of nitrite

Porous nanododecahedron of Co 3 O 4 /C has been synthesized by calcination of the ZIF-67 in air at 400 °C and then be used as electrode material for fabricating a highly sensitive and low overpotential sensor of nitrite ion (NO 2 − ). The structure and morphology characterization show that ZIF-67 behaves as an ideal sacrificial template for preparing Co 3 O 4 /C with regular shape. The two components of Co 3 O 4 and carbon are uniformly distributed in the composite. Electrochemical analysis shows that the excellent electrocatalysis performance toward the oxidation of NO 2 − is based on the synergy of Co 3 O 4 and carbon in the nanocomposite. At NO 2 − concentration from 2 nM to 8 mM, a fast response time within 3 s is revealed and 1.21 nM of detection limit is achieved. The sensor is also reliable to analysis of NO 2 − existed in the real samples of soil leaching liquid and macrophage supernate.