Chonglin Wang,Peng Gao,Xiang Yao,Xiaohui Sun,Hong Du
Metal-organic framework (MOF) materials have been extensively utilized as catalysts for the oxygen evolution reaction (OER) due to their remarkable properties. To enhance electrocatalytic performance, the modifying MOF materials has emerged as a significant research area. In this study, we synthesized MIL-100(Fe), and MOF-74(Co) MOF materials on the surface of NiCo-ZIF using 2,5-dihydroxyterephthalic acid as the ligand , successfully obtaining a ternary MOFs composite material designated as NiCo-ZIF@MM. Experimental results demonstrated that the NiCo-ZIF@MM composite formed a heterogeneous structure, which significantly enhanced electron transport efficiency and catalytic activity. Additionally, this novel material exhibits a larger electrochemical active surface area and excellent stability. Notably, the overpotential of NiCo-ZIF@MM is reduced to 190 mV at a current density of 10 mA/cm2. This study not only achieves effective modification of ZIF materials but also provides a new strategy for the development of highly efficient and stable MOF-based OER catalysts.
Metal–organic frameworks (MOFs) have attracted much interest in electrocatalysis as promising catalysts in recent years. However, it still remains a challenge to directly use MOF-based materials as bifunctional electrocatalysts for overall water splitting. Herein, a hierarchical Co,Fe-MOF-74/Co/carbon cloth (CC) three-layer hybrid electrode is synthesized by a simple electrochemical deposition technology with subsequent solvothermal treatment. Electrochemical performance investigations show that the as-constructed Co,Fe-MOF-74/Co/CC electrode exhibits impressive electrocatalytic activity for full water splitting, which only requires a low overpotential of 226 mV@20 mA cm–2 for the oxygen evolution reaction (OER) and 94 mV@–10 mA cm–2 for the hydrogen evolution reaction (HER), respectively. Employing the as-constructed electrode as the anode and cathode in a two-electrode setup simultaneously, only 1.65 V of the voltage is needed to deliver the current density of 20 mA cm–2. The above excellent electrochemical performances should be attributed to the specific architecture, the synergistic effect of the Co and Fe species, and the superhydrophilic surface of the catalyst. More importantly, further investigations uncover that metal hydroxides and oxyhydroxides produced in situ during electrochemical tests are the veritable active species, which promote the high catalytic activity of the present catalyst.
危险品化学品经营许可证（带存储）