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Fe‐Doped Nickel Hydroxide/Nickel Oxyhydroxide Function as an Efficient Catalyst for the Oxygen Evolution Reaction
Author(s) -
Mahala Chavi,
Devi Sharma Mamta,
Basu Mrinmoyee
Publication year - 2019
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201900857
Subject(s) - tafel equation , overpotential , oxygen evolution , nickel , hydroxide , catalysis , inorganic chemistry , dopant , materials science , electrocatalyst , electrochemistry , x ray photoelectron spectroscopy , doping , chemistry , chemical engineering , metallurgy , electrode , organic chemistry , optoelectronics , engineering
Abstract Designing metal hydroxide electrocatalysts with high efficiency to overcome the slow reaction kinetics of the oxygen evolution reaction (OER) is considered as a significant approach for renewable energy resources. We report here a simple methodology to synthesize 2D thin nickel hydroxide/nickel oxyhydroxide sheets that show efficient activity towards OER. Further, by doping with a heteroatom, Fe, thinner sheets of nickel hydroxide/nickel oxyhydroxide are developed, which exhibit enhanced electrocatalytic activity towards OER with high durability. Fe‐doped Ni(OH) 2 /NiOOH requires only 200 mV overpotential to produce 10 mA/cm 2 , whereas bare Ni(OH) 2 /NiOOH needs 290 mV overpotential. Moreover, Fe‐doped nickel hydroxide/nickel oxyhydroxide shows a minimal Tafel value of 48 mV/decade, which is even lower than RuO 2 /CC (82 mV/decade). X‐ray photoelectron spectroscopy indicates that in the case of Fe‐doped Ni(OH) 2 /NiOOH, the Ni 3+ signal enhances, which indicates the favourable stabilization of Ni 3+ in the presence of Fe 3+ dopant. Under electrochemical OER conditions, in Fe‐doped Ni(OH) 2 /NiOOH, Fe 3+ species help to generate more Ni 3+ , which function as the active species. Fe 0.06 Ni 0.94 (OH) 2 /NiOOH shows long‐term stability for at least 24 hours in alkaline medium. This work unveils a green strategy for Fe‐doping in 2D thin sheets of Ni(OH) 2 /NiOOH, which show improved electrocatalytic activity compared to bare Ni(OH) 2 /NiOOH. The mechanism of OER activity enhancement after Fe‐doping is proposed here.