Rare-Earth-Based Bimetallic Metal–Organic Frameworks Promote Oxygen Electrocatalysis for Rechargeable Zn–Air Batteries

Abstract

Metal−organic frameworks (MOF) are versatile and good structurally stable materials that are widely used in energy conversion and storage. In this work, rare-earth-based bimetallic metal−organic framework (NiY-BTC) nanorods anchored with transition metal−organic frameworks (ZIF-67) were used as versatile precursors to prepare novel metal/rare-earth metal oxidecoupled carbon-based bifunctional oxygen electrocatalysts (NiY/C@Co/C). Due to the stable nanorods framework structure, appropriate Y 2 O 3 active center, and richness of Co−N sites in the carbon skeletons, the NiY/C@Co/C catalyst exhibits high onset potentials (E onset = 0.928 V) and half-wave potential (E 1/2 = 0.83 V) for the oxygen reduction reaction (ORR), and expresses a low overpotential (η = 392 mV@10 mA cm −2 ) for the oxygen evolution reaction (OER). Moreover, a rechargeable Zn−air battery assembled with NiY/C@Co/C as the air cathode catalyst displayed a great specific capacity (899.6 mAh gZn −1 ) and a remarkable peak power density of 102.2 mW cm −2 , as well as excellent durability and stability. This work delivers a way using rare-earth metal− organic frameworks to get the corresponding metal oxide-coupled carbon-based bifunctional oxygen electrocatalysts for rechargeable Zn−air batteries.

Rare earth oxide based electrocatalysts: synthesis, properties and applications

“…220,221 Lei et al prepared a RE-based NiY-BTC nanorod anchored transition ZIF-67 as a multifunctional precursor and prepared a novel metal/RE metal oxidative coupling carbon based bifunctional oxygen electrocatalyst (NiY/C@Co/C). 222 NiY/C@Co/C catalyst shows a stable nanorod skeleton structure, a suitable Y 2 O 3 active center and rich Co-N sites and has high onset potential (E onset = 0.928 V) and halfwave potential (E 1/2 = 0.83 V) for the ORR (Fig. 12d and e).…”

Rare earth-based MOFs for photo/electrocatalysis

“…186 However, the large overpotential and low electrochemical energy conversion efficiency involved in the hydrogen evolution reaction process have become the main obstacles. 187 7c. Er-MOF/MoS 2 has a high current density and area.…”

“…186 However, the large overpotential and low electrochemical energy conversion efficiency involved in the hydrogen evolution reaction process have become the main obstacles. 187 Liao et al synthesized the erbium-based MOF material with 1,3,5-benzenetricarboxylic acid as the ligand by the hydrothermal method. Er-MOF/MoS 2 was obtained by doping MoS into MOF material by adjusting the pH.…”

Interfacial Coupling of Gadolinium-2-methylimidazole Metal Organic Framework and 2D-g-C3N4 Nanosheet for Synergistically Enhanced Bifunctional Oxygen Electrocatalysis

“…25−27 The distinct electron configuration, unfilled 4f orbital, and filled 5s−5p orbital shielding of rare earths provide electronic stability by exhibiting an enhancement in oxygen electrocatalysis. 19,20,28,29 The surface functionalities and interfacial characteristics are further modulated through selection of coordinating ligands with suitable metal ions. Considerably, the weak basic site (−NH) of 2-mim provides more reactive species by linking to metallic cations via covalent bonding.…”

“…These limitations hinder their ability to overcome the thermodynamic barrier associated with the OOH intermediate at low overpotentials, thus impeding the efficiency of the overall oxygen electrocatalysis process. Also, numerous studies have explored transition-metal-based MOFs (e.g., Zn-MOF, Ni-MOF, Fe-MOF, Co-MOF) in the context of electrocatalysis, − but rare-earth metals exhibit a propensity for forming stable compounds. − The distinct electron configuration, unfilled 4f orbital, and filled 5s–5p orbital shielding of rare earths provide electronic stability by exhibiting an enhancement in oxygen electrocatalysis. ,,, The surface functionalities and interfacial characteristics are further modulated through selection of coordinating ligands with suitable metal ions. Considerably, the weak basic site (−NH) of 2-mim provides more reactive species by linking to metallic cations via covalent bonding. , The lone pair of the nitrogen atom coordinates with the cations.…”