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Title: In Situ Electrochemical Oxidation Tuning of Transition Metal Disulfides to Oxides for Enhanced Water Oxidation

The development of catalysts with earth-abundant elements for efficient oxygen evolution reactions is of paramount significance for clean and sustainable energy storage and conversion devices. Our group demonstrated recently that the electrochemical tuning of catalysts via lithium insertion and extraction has emerged as a powerful approach to improve catalytic activity. Here we report a novel in situ electrochemical oxidation tuning approach to develop a series of binary, ternary, and quaternary transition metal (e.g., Co, Ni, Fe) oxides from their corresponding sulfides as highly active catalysts for much enhanced water oxidation. The electrochemically tuned cobalt–nickel–iron oxides grown directly on the three-dimensional carbon fiber electrodes exhibit a low overpotential of 232 mV at current density of 10 mA cm–2, small Tafel slope of 37.6 mV dec–1, and exceptional long-term stability of electrolysis for over 100 h in 1 M KOH alkaline medium, superior to most non-noble oxygen evolution catalysts reported so far. The materials evolution associated with the electrochemical oxidation tuning is systematically investigated by various characterizations, manifesting that the improved activities are attributed to the significant grain size reduction and increase of surface area and electroactive sites. This work provides a promising strategy to develop electrocatalysts for large-scale water-splitting systems andmore » many other applications.« less
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [2]
  1. Stanford Univ., CA (United States)
  2. SLAC National Accelerator Lab., Menlo Park, CA (United States). Stanford Institute for Materials and Energy Science (SIMES); Stanford Univ., CA (United States)
Publication Date:
OSTI Identifier:
1194823
Grant/Contract Number:
AC02-76-SFO0515
Type:
Published Article
Journal Name:
ACS Central Science
Additional Journal Information:
Journal Volume: 1; Journal Issue: 5; Journal ID: ISSN 2374-7943
Publisher:
American Chemical Society (ACS)
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 25 ENERGY STORAGE