Premium
Engineering Nanoporous Iron(III) Oxide into an Effective Water Oxidation Electrode
Author(s) -
Haschke Sandra,
Wu Yanlin,
Bashouti Muhammad,
Christiansen Silke,
Bachmann Julien
Publication year - 2015
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201500623
Subject(s) - nanoporous , dielectric spectroscopy , materials science , electrochemistry , oxide , electrolyte , x ray photoelectron spectroscopy , nanopore , electrode , atomic layer deposition , current density , annealing (glass) , chemical engineering , analytical chemistry (journal) , chemistry , nanotechnology , layer (electronics) , composite material , physics , quantum mechanics , chromatography , metallurgy , engineering
The geometric effects of nanostructuring a pure Fe 2 O 3 surface on its electrochemical water oxidation performance at neutral pH were systematically explored. Atomic layer deposition was used to coat the inner walls of cylindrical “anodic” nanopores ordered in parallel arrays with a homogeneous Fe 2 O 3 layer. Annealing and electrochemical treatments generated a roughened surface, as demonstrated by X‐ray photoelectron spectroscopy and electrochemical impedance spectroscopy, the larger geometric area of which increases current densities. Combining these treatments with the “anodic” pore geometry delivered an effective increase in turnover by almost three orders of magnitude with respect to a smooth, planar Fe 2 O 3 surface. However, the current density depended on the pore length in a non‐monotonic manner. An optimal length was found that maximized turnover by equating the rate of transport in the electrolyte with that of charge transfer across the interface.