| Abstrakt: |
Here, a general method for fabricating active electrocatalysts is introduced for oxygen evolution reaction (OER) based on multimetallic (ternary alloy) structures formed on the N-doped nanoporous carbon platform without using ruthenium or iridium. Accordingly, three different sizes, small, medium, and large, of cobalt zeolitic imidazolate framework-67 (ZIF67X, X: S, M, L) are synthesized. Then, the product is carbonized via direct pyrolysis at 800 °C in an argon atmosphere to yield nitrogen-doped nanoporous carbon composited with cobalt nanoparticles (PZIF67X800). To improve the activity, the most active nanoporous system for OER (PZIF67L800) is further modified by electrochemical deposition of Co, Ni, and Fe (PZIF67L800-CoNiFe). The electrochemical results revealed a large electrocatalytic activity for the GC-PZIF67L800-CoNiFe toward the OER in alkaline media, Tafel slopes of 72 mV dec−1 and overpotentials of 314 mV at 30 mA cm−2 (η30), compared with those obtained under the same conditions on GC-RuO2 (99 mV dec−1 and 499 mV). The improved activity is attributed to (i) the increase in active surface area and simultaneous formation of Co nanoparticles and nitrogen-doped porous carbon, causing uniformly dispersed metal nanoparticles in the composite, and (ii) synergistic effect between the ingredients of ternary alloy nanoparticles (CoNiFe-NPs) and nitrogen-doped carbon nanoporous platform. [ABSTRACT FROM AUTHOR] |
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