Self-supported Co-doped FeNi carbonate hydroxide nanosheet array as a highly efficient electrocatalyst towards the oxygen evolution reaction in an alkaline solution

Zeitschrift anorg allge chemie

et al. 2020

Self Cite

Developing earth‐abundant, highly active and long‐term durable electrocatalysts for oxygen evolution reaction (OER) is highly desirable and great challenging for large‐scale industrial application of electrochemical water splitting. Herein, in‐situ growth of uniform nanosheet arrays on nickel foam (NF) is hydrothermally achieved by varying feed ratios of FeIII and NiII salts. The feed ratio of the two active metals has significantly dominated both the morphological and electronic structures of the resultant electrocatalysts, leading to feed ratio‐dependent volcano‐type OER activity. The optimized Fe0.89Ni0.11‐BDC/NF exhibits the best OER performance, affording a low overpotential of 220 mV to drive a current density of 50 mA·cm–2 with small Tafel slope of 44.8 mV·dec–1 and long‐lasting stability over 20 hours. The synergistic effect from the FeIII and NiII species on both the morphological and electronic structure modulations have dramatically accelerated the reaction kinetics, responsible eventually for the enhanced OER activity. This work provides valuable information for nanostructured MOFs as efficient electrocatalysts.

Section: Resultsmentioning

confidence: 99%

Heterometallic Feed Ratio‐Dominated Oxygen Evolution Activity in Self‐Supported Metal‐Organic Framework Nanosheet Arrays Electrocatalyst

Zeitschrift anorg allge chemie

et al. 2020

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“…Non‐noble iron and cobalt‐based electrocatalysts have owned promising OER performances due to their adjustable electronic structures and controllable morphologies. Various modifications, including but not limited to doping the third metal for optimizing absorption energy of water molecule, combining with carbon materials for accelerating the conductivity as well as coupling with heterogeneous nanoparticles or amorphous metal oxides for strengthening the interfacial interactions, have been successively achieved to further improve the OER activity . In particular, defect engineering has very recently emerged as one of most effective and versatile strategies for the performance enhancement.…”

Section: Figurementioning

confidence: 99%

Nickel Foam‐Supported Amorphous FeCo(Mn)−O Nanoclusters with Abundant Oxygen Vacancies through Selective Dealloying for Efficient Electrocatalytic Oxygen Evolution

et al. 2020

ChemElectroChem

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Developing earth‐abundant, cost‐effective and high‐performance electrocatalyst towards the oxygen evolution reaction (OER) is a great challenge for large‐scale hydrogen production from electrochemical water splitting. Nickel‐foam‐supported amorphous hierarchical nanoclusters of metal/metal (hydr)oxides with abundant oxygen defects (FeCo(Mn)−O/NF) were prepared from an FeCoMn/NF precursor through chemical dealloying. The FeCo(Mn)−O/NF electrode exhibits enhanced OER activity in alkaline electrolyte with an overpotential of only 235 mV to drive a current density of 10 mA cm−2, a small Tafel slope of 44.5 mV dec−1 and excellent durability over 100 h. The superior OER performance is attributed to the synergistic effect of abundant oxygen vacancies, hierarchical morphology and amorphous structure, which essentially modulate the electronic structures and create more active sites. These interesting findings highlight the significance of dealloying strategy on the structural defects and improved catalytic performance of the electrocatalysts.

“…Recently, transition metals have been widely investigated for nonprecious metallic electrocatalysts toward rechargeable zinc-air batteries . Among the transition metals, the cobalt (Co) element is low-cost, earth-abundant, and environment-friendly and has been applied for ORR electrocatalysts . For instance, cobalt oxide catalysts exhibit comparable ORR activity and long-term stability with platinum-based materials .…”

Section: Introductionmentioning

confidence: 99%

Cobalt Oxide Nanoparticles/Nitrogen-Doped Graphene as the Highly Efficient Oxygen Reduction Electrocatalyst for Rechargeable Zinc-Air Batteries

ACS Sustainable Chem. Eng.

Deng

et al. 2019

Environmentally friendly and inexpensive oxygen catalysts with high-efficient activity are paramount for powering zinc-air batteries. Here, cobalt oxide nanoparticles confined in nitrogen-doped graphene (CoO/NG) were produced as the oxygen reduction electrocatalyst for zinc-air batteries by hydrothermal and high-temperature calcination. During the hydrothermal process, the graphitic carbon nitride as the self-sacrificing template can be partially converted into a carbanion (CO3 2–) in the presence of cobalt-based ionic liquid ([N1444]Cl/CoCl2), which can generate cobalt carbonate (CoCO3) with Co2+. During the high-temperature calcination, CoCO3 is decomposed into CoO embedded into nitrogen-doped graphene and escaped CO2, which can increase specific surface areas of oxygen reduction electrocatalysts. The as-prepared CoO/NG shows not only abundant mesoporous structures but also large specific surface area. The CoO/NG exhibits outstanding oxygen reduction performance (E 1/2 ≈ 0.830 V versus RHE). Additionally, the zinc-air battery manufactured by CoO/NG generates a specific capacity of 815.6 mA h g–1. It is verified that the CoO/NG catalyst as the air-cathode is promising in actual application of zinc-air batteries.