Fused Hybrid Linkers for Metal–Organic Frameworks-Derived Bifunctional Oxygen Electrocatalysts

Abstract

<div> <div> <div> <p>Preparation of electrocatalysts often relies on the use of multiple starting materials – inorganic salts or organometallic precursors, nanostructured carbon supports, organic additives, dopants and carbonization under modifying atmospheres (e.g. NH<sub>3 </sub>or H<sub>2</sub>) – with the examples of electrocatalysts arising from a single precursor being much less common. Herein, we have surveyed a series of heterobivalent scaffolds to identify an iron/benzimidazole-based metal– organic framework as a uniform starting material. By merging the catechol and imidazole units together, we get direct entry into a highly efficient bifunctional oxygen electrocatalyst, which alleviates the need for additional dopants and modifying conditions (ORR: <i>E</i><sub>on</sub> = 1.01 V, <i>E</i><sub>1/2</sub> = 0.87 V vs. RHE in 0.1 M KOH; OER: 1.60 V @10 mA cm<sup>–2</sup> in 0.1 M KOH; ∆<i>E</i> = 0.73 V). We demonstrate that by fine-tuning the chemical nature of an organic linker, one is able modulate the electrochemical properties of a single precursor-derived electrocatalyst material. </p> </div> </div> </div>