Bifunctional MOF‐on‐MOF‐Derived CuCo2O4 for Oxygen Evolution Reaction Electrocatalysis and Supercapacitor Electrodes

The development of high‐performance electrocatalysts for oxygen evolution reaction (OER) is still a challenge to produce green hydrogen. Thus, herein, a new bifunctional metal–organic frameworks (MOF)‐derived CuCo 2 O 4 is obtained, applied as OER electrocatalyst and electrode for supercapacitors. All physicochemical and morphological characterization indicates the formation of a pure spinel structure CuCo 2 O 4 crystalline phase and coral reef‐like morphology. X‐ray photoelectron spectroscopy data showed major presence of Co 3+ and Cu + ions on the surface and high concentration of oxygen vacancies. OER electrocatalytic assays conducted in alkaline medium (1.0 M KOH) show a reduced overpotential ( η ) of 317 mV at 10 mA cm −2 and Tafel slope of only 49 mV dec −1 , besides excellent electrochemical stability up to 12 h. The material is also studied for supercapacitors applications via cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) analysis. CuCo 2 O 4 material presents specific capacity near 75 C g −1 , at least ≈2.8 times higher than pristine CuO and Co 3 O 4 at 1 A g −1 . This results indicate the MOFs‐derived CuCo 2 O 4 as a promising bifunctional material for energy conversion and storage.