Premium
A simple preparation of Co 0. 75 Fe 0 .25 hydrous oxide nanoparticles as active electrocatalysts for water oxidation reaction
Author(s) -
Wang Chao,
Chai Le,
Tian Qianhong,
Liu Shuling
Publication year - 2020
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.5428
Subject(s) - overpotential , tafel equation , nanoparticle , hydroxide , oxide , dissolution , x ray photoelectron spectroscopy , aqueous solution , inorganic chemistry , catalysis , chemistry , electrochemistry , electrocatalyst , materials science , chemical engineering , electrode , nanotechnology , biochemistry , organic chemistry , engineering
Summary A serious of CoFe hydrous oxide nanoparticles (Co 1−z Fe z O x H y NP [z = 0‐1]) were synthesized by stirring CoCl 2 and FeCl 2 in aqueous KOH solutions for 0.5 hours, and the resulting nanoparticles are active electrocatalysts for water oxidation reaction (WOR) in alkaline solutions. The Co 0.75 Fe 0.25 O x H y NP, which are the most active electrocatalysts, have a layered double hydroxide (LDH) structure, with the average particle sizes about 16 nm. When using Ni foam as the substrate, the electrode with Co 0.75 Fe 0.25 O x H y NP as catalysts exhibited an overpotential of 284 mV for WOR in 1 M KOH at 10 mA cm −2 . The Tafel slope was 43 mV dec −1 , and the TOF was 1.30 s −1 at 350 mV overpotential (loading Co + Fe = 0.133 mg cm −2 ). The Co 0.75 Fe 0.25 O x H y NP are robust toward long‐term galvanostatic test and showed less than 2% dissolution in 10 hours. Preliminary kinetic study suggests that the presence of Fe in Co 1−z Fe z O x H y NP alters the WOR mechanistic pathways. The increased number of electrochemically active sites endowed by the LDH structure and the electronic interactions between Co and Fe as suggested by XPS, both contribute to the enhanced WOR activity.