Defect-Rich Co3O4/CN Composites Derived from MOF/CN via Solvent-Free Synthesis for Efficient Electrocatalytic Oxidation

Co 3 O 4 is a promising electro-oxidation catalyst, which is applicable to the oxygen evolution reaction (OER) and glucose oxidation reaction (GOR). However, its insufficient active sites and poor conductivity severely restrict its practical application. Herein, a Co 3 O 4 /CN electrocatalyst derived from zeolitic imidazolate framework (ZIF)-67/CN was successfully synthesized via a solvent-free strategy for efficient OER and GOR. In electrocatalytic OER, Co 3 O 4 /CN demonstrated superior performance on a glassy carbon (GC) electrode, achieving an overpotential ( η ) of 306 mV at a current density ( j ) of 10 mA cm −2 , which outperformed Co 3 O 4 -ZIF (Co 3 O 4 /CN derived from ZIF-67). Furthermore, the Co 3 O 4 /CN electrocatalyst also exhibited good GOR ability, with high sensitivity of 1021.9 μA mM −1  cm −2 , a low detection limit of 1.8 μM ( S / N  = 3), a broad linear range from 2 μM to 2.1 mM, excellent repeatability and reproducibility (relative standard deviation [RSD] < 6%), and long-term stability up to 3 weeks. The enhanced activity may be ascribed to the rich active sites, porous structure, and improved electrical conductivity of Co 3 O 4 /CN. This work provides a feasible strategy for enhancing electrocatalytic activity toward OER and GOR using metal–organic framework (MOF)/CN-based materials.