ZIF-67 Derived Co₃O₄/rGO Electrodes for Electrochemical Detection of H₂O₂ with High Sensitivity and Selectivity

In this work, zeolitic imidazolate framework (ZIF) nanocrystal arrays were supported by graphene oxide (GO) nanosheets by a graphene assembly route. Then, ZIF-67/GO was transformed into nanoporous Co₃O₄/rGO composites through calcination. Both ZIF-67/GO and Co₃O₄/rGO were employed as active materials to modify glass carbon electrodes for hydrogen peroxide (H₂O₂) non-enzymatic sensor. The measurement results indicate that ZIF-67/GO presented excellent electro-catalytic activity towards H₂O₂ with a linear range of 0.1-22.9 mM and a low detection limit of 1.92 mM. More important, the Co₃O₄/rGO modified GC electrode showed higher detection sensitivity for H₂O₂ and the limit of detection can be as low as 7.87 nM. Furthermore, ZIF-67/GO and Co₃O₄/rGO modified electrodes both exhibited excellent selectivity in phosphate buffer solution and NaOH.