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Efficient and Highly Transparent Ultra‐Thin Nickel‐Iron Oxy‐hydroxide Catalyst for Oxygen Evolution Prepared by Successive Ionic Layer Adsorption and Reaction
Author(s) -
GarciaTorregrosa Ivan,
Goryachev Andrey,
Hofmann Jan P.,
Hensen Emiel J. M.,
Weckhuysen Bert M.
Publication year - 2019
Publication title -
chemphotochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.13
H-Index - 18
ISSN - 2367-0932
DOI - 10.1002/cptc.201900131
Subject(s) - oxygen evolution , overpotential , adsorption , electrolysis of water , catalysis , nickel , electrolysis , chemical engineering , ionic bonding , materials science , inorganic chemistry , water splitting , hematite , hydroxide , electrode , chemistry , photocatalysis , electrochemistry , ion , electrolyte , metallurgy , biochemistry , organic chemistry , engineering
NiFeO x thin films prepared by successive ionic layer adsorption and reaction (SILAR) were deposited onto nanostructured hematite (Fe 2 O 3 ) photoanodes and their effect on the current density and photo‐onset potential was studied. After optimization of bath concentration, immersion times, and number of SILAR cycles, very conformal and active NiFeO x films with controlled Fe/Ni content ratios were obtained. Upon the incorporation of Fe 2+ species in the NiCl 2 solution bath, a cathodic shift in the overpotential required for the oxygen evolution reaction (OER) by more than 200 mV with no decrease in current density was observed after 40 SILAR cycles. We demonstrate that by fine‐tuning the film composition and thickness, NiFeO x can be employed as an efficient OER catalyst with very low absorbance in the visible spectrum. By doing so, we demonstrate that this material has great potential for incorporation in semiconductor photoelectrodes for direct solar‐driven water electrolysis. Being a simple water‐based layer‐by‐layer growth method, SILAR offers promise for the synthesis of catalyst coatings in nano‐structured and high surface area electrodes.