Strong electronic interaction enhanced electrocatalysis of copper phthalocyanine decorated Co-MOF-74 toward highly efficient oxygen evolution reaction

Abstract

Metal–organic frameworks (MOFs) have been identified as promising electrocatalysts for the oxygen evolution reaction (OER). However, most of the reported MOFs have low electrical conductivity and poor stability, and therefore addressing these problems is crucial for achieving higher electrocatalytic performance. Meanwhile, direct observations of the electrocatalytic behavior, which is of great significance to the understanding of the electrocatalytic mechanism, remain highly challenging. Here, we report on a significant electrocatalytic performance enhancement of Co-MOF-74 for the OER after decoration by copper phthalocyanine (CuPc) molecules. Co-MOF-74@CuPc, synthesized by solvothermal reactions, displays a low overpotential of 293 mV and a robust long-term stability (70 h) at 10 mA cm⁻². The enhancement has been attributed to strong electronic interaction between the π-conjugated CuPc molecule and Co-MOF-74, which promotes the electron transfer, increases the electrocatalytic active surface area and regulates the electronic structure during the OER process.