Moreno, JA;
Khan, MA;
Ivanov, YP;
Lopatin, S;
Holguín-Lerma, JA;
Marinaro, G;
Ooi, BS;
... Kosel, J; + view all
(2019)
Growth of Ordered Iron Oxide Nanowires for Photo-electrochemical Water Oxidation.
ACS Applied Energy Materials
, 2
(12)
pp. 8473-8480.
10.1021/acsaem.9b01343.
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Abstract
This work reports the synthesis of ordered and vertically aligned iron oxide nanowires for photo-electrochemical (PEC) water oxidation. The nanowires exhibited promising PEC activity for water oxidation with saturated photocurrents of ∼0.8 mA cm-2 at 1.23 V vs RHE. Various factors inevitably affect their photochemical activity such as crystallinity, morphology, compositional gradient, and surface states. They were studied with HRTEM, EELS, and Raman shift techniques. The nanowires had complex compositional and morphological structures at nano and atomic scales. The nanowires annealed at 350 °C had an outer shell dominated by Fe3+ cations, while the core had mixed oxidation states of iron cations (+2 and +3). In contrast, nanowires annealed at 450 °C are fully oxidized with Fe3+ cations only and were found to be more active. At the same time, we observed anisotropic compositional gradients of nickel cations inside the iron oxide, originating from the nickel support film. Our work shows that the methodology used can affect the composition of the surface and near surface of the grown nanowires. It therefore points out the importance of a detailed analysis, in order to obtain a realistic structure-activity relationship in photo-electrocatalysis.
| Type: | Article |
|---|---|
| Title: | Growth of Ordered Iron Oxide Nanowires for Photo-electrochemical Water Oxidation |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1021/acsaem.9b01343 |
| Publisher version: | https://doi.org/10.1021/acsaem.9b01343 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Iron, Oxides, Diffusion, Nanowires, Electrodes |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10084345 |
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