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Overpotential

About: Overpotential is a research topic. Over the lifetime, 16474 publications have been published within this topic receiving 616632 citations.


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Journal ArticleDOI
Yang Liu1, Jing Li1, Feng Li1, Wenzhu Li1, Haidong Yang1, Xueyao Zhang1, Yansheng Liu1, Jiantai Ma1 
TL;DR: In this article, a polyaniline-multiwalled carbon nanotube (PANI-MWCNT) supported, high performance CoFe2O4 nanoparticle (NP) loaded electrocatalyst was synthesized through a novel and simple in situ process under mild conditions.
Abstract: Designing and preparing highly efficient non-precious metal electrocatalysts for the oxygen evolution reaction (OER) is extremely urgent but still remains a challenge. In this study, a polyaniline–multiwalled carbon nanotube (PANI-MWCNT) supported, high performance CoFe2O4 nanoparticle (NP) loaded electrocatalyst (CoFe2O4/PANI-MWCNTs) is synthesized through a novel and simple in situ process under mild conditions. It is found that the introduction of PANI improves the synergistic effect between the CoFe2O4 NPs and MWCNTs, so as to promote the electrical conductivity and stability of the catalyst. Meanwhile, PANI provides more active sites to attach CoFe2O4 NPs uniformly and tightly. Electrochemical measurement shows that the electrocatalyst displays excellent OER activities at a low overpotential of 314 mV for 10 mA cm−2 current density and a small Tafel slope of 30.69 mV dec−1 in 1 M KOH at a scan rate of 5 mV s−1. Furthermore, this electrocatalyst exhibits remarkably good durability evaluated by continuously cycling for 1000 cycles and stably working at 0.54 V (vs. Ag/AgCl) for at least 40 h. The achieved results confirm that the CoFe2O4/PANI-MWCNT hybrid is an earth-abundant and cheaply fabricated anode material for OER.

161 citations

Journal ArticleDOI
TL;DR: It is demonstrated that the double perovskite LaFex Ni1-x O3 (LFNO) nanorods (NRs) can be adopted as highly active and stable OER electrocatalysts.
Abstract: Perovskite-based electrocatalysts are one of the most promising materials for oxygen evolution reaction (OER), but their activity and durability are still far from desirable. Herein, we demonstrate that the double perovskite LaFex Ni1-x O3 (LFNO) nanorods (NRs) can be adopted as highly active and stable OER electrocatalysts. The optimized LFNO-II NRs with Ni/Fe ratio of 8:2 achieve a low overpotential of 302 mV at 10 mA cm-2 and a small Tafel slope of 50 mV dec-1 , outperforming those of the commercial Ir/C. The LFNO-II NRs also show high OER stability with slight current decrease after 20 h. The enhanced activity is explained by the improved surface area, tailored electronic structure as well as strong hybridization between O and Ni.

161 citations

Journal ArticleDOI
TL;DR: The bonding between single nickel and oxygen sites results in the extraordinary boosting of OER performance of Ni‐O‐G SACs, which opens numerous opportunities for creating unconventional Sacs via metal–oxygen bonding.
Abstract: Single-atom catalysts (SACs) are efficient for maximizing electrocatalytic activity, but have unsatisfactory activity for the oxygen evolution reaction (OER). Herein, the NaCl template synthesis of individual nickel (Ni) SACs is reported, bonded to oxygen sites on graphene-like carbon (denoted as Ni-O-G SACs) with superior activity and stability for OER. A variety of characterizations unveil that the Ni-O-G SACs present 3D porous framework constructed by ultrathin graphene sheets, single Ni atoms, coordinating nickel atoms to oxygen. Consequently, the catalysts are active and robust for OER with extremely low overpotential of 224 mV at current density of 10 mA cm-2, 42 mV dec-1 Tafel slope, oxygen production turn over frequency of 1.44 S-1 at 300 mV, and long-term durability without significant degradation for 50 h at exceptionally high current of 115 mA cm-1, outperforming the state-of-the-art OER SACs. A theoretical simulation further reveals that the bonding between single nickel and oxygen sites results in the extraordinary boosting of OER performance of Ni-O-G SACs. Therefore, this work opens numerous opportunities for creating unconventional SACs via metal-oxygen bonding.

161 citations

Journal ArticleDOI
TL;DR: In this paper, mutually beneficial Co3O4@MoS2 heterostructures were adopted to efficiently balance both HER and OER performance by improving the sluggish kinetics, which synergistically favored the reduction of the energy barrier of the initial water dissociation step and optimization of the subsequent H adsorption/desorption for MoS2 in alkaline HER.
Abstract: Designing low-cost and highly efficient bifunctional electrocatalysts for compatible integration with the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) for overall water splitting is critical but challenging. Herein, mutually beneficial Co3O4@MoS2 heterostructures were adopted to efficiently balance both HER and OER performance by improving the sluggish kinetics. These heterostructures synergistically favoured the reduction of the energy barrier of the initial water dissociation step and optimization of the subsequent H adsorption/desorption for MoS2 in alkaline HER. Moreover, the adsorption of oxygen intermediates was enhanced for Co3O4 in the OER process. As a result, the Co3O4@MoS2 heterostructures showed excellent overall water splitting performance with a low overpotential and Tafel slope.

161 citations

Journal ArticleDOI
TL;DR: It is discovered that it is the overpotential of the sodium counter electrode that drives the half-cells to the lower cutoff potential prematurely during hard carbon sodiation, particularly at high current rates, which prevents the hard carbon anode from being fully sodiated.

161 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20232,316
20224,268
20212,838
20202,411
20192,174
20181,740