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

Abstract

Noble metal free M-N-C oxygen electrocatalysts are generaly synthesized using inorganic salts, organometallic precursors, nanostructured carbon nanotubes, several dopants and carbonization under modifying environments such as NH 3 or H 2 . Reducing synthesis steps or bringing versatility in post product is quite rare. We have introduced a series of metal-organic frameworks using iron/benzimidazole as the only primary precursor to obtain a uniform material. By merging catechol and imidazole units together, we prepared efficient bifunctional oxygen electrocatalyst. The proposed material outperforms the Pt-based materials with respect to electrocatalytic properties in alkaline media (ORR: E on = 1.01 V, E 1/2 = 0.87 V vs. RHE in 0.1 M KOH; OER: 1.60 V @10 mA cm –2 in 0.1 M KOH; ΔE = 0.73 V). It was also established that fine-tuning of organic linker can help to modulate the electrochemical properties of the single precursor based electro-catalyst material.