Single-Atom Implanted Two-dimensional MOFs as Efficient Electrocatalysts for Oxygen Evolution Reaction
The exploration of novel electrochemical energy conversion and storage devices has been extensively studied in recent decades for their specific advantages. Therefore, the design of highly efficient, stable, and noble‐metal‐free electrocatalysts for oxygen-related reactions (OER) is critical but challenging, which is still worth improving. Herein, a facile and controllable synthesis strategy for bimetallic electrocatalysts for OER from a two-dimensional iron-based Metal‐Organic Framework (HUST-8, HUST = Huazhong University of Science and Technology) precursor had been reported. The unoccupied porphyrin center had been disposed into the layer structure of HUST-8, which is very facile for the introduction of second types of metal center via post-modified treatment. Guided by the synthesis strategy, Fe/Ni, Fe/Co, Fe/Zn, Fe/Mn and Fe/Fe species had been fabricated, and their electrocatalytic performance for OER had been further characterized, in which Fe/Ni type exhibits the best efficiency and conversion. For Fe/Ni species of HUST-8 (labeled as Ni@HUST-8), in 1M KOH, the initial potential for OER activity performance is 170mV (vs RHE). At 10 mA cm-2, the corresponding overpotential is 240mV and the slope of Tafel is simulated as 60.8 mv dec-1. All of these experimental results of Ni@HUST-8 illustrate the better performance than commercial IrO2. Compared to the MOF parent and other bimetallic species, the higher electrocatalytic performance of Ni@HUST-8 should be ascribed to the special synergistic effect of Fe and Ni centers, which tends to greatly improve reaction kinetics and charge transfer efficiency, while increase the activity of OER and achieve the best catalytic performances. The systematical investigation clearly manifest the important role of synergistic effect of bimetallic centers towards OER, and explore the other insight into fabricating the tailored electrocatalysts derived from MOF-based templates.