Nanostructured Ternary FeCrAl Oxide Photocathodes for Water Photoelectrolysis

Kondofersky, Ilina; Müller, Alexander; Dunn, Halina K.; Ivanova, Alesja; Štefanić, Goran; Ehrensperger, Martin; Scheu, Christina; Parkinson, Bruce A.; Fattakhova-Rohlfing, Dina and Bein, Thomas (2016): Nanostructured Ternary FeCrAl Oxide Photocathodes for Water Photoelectrolysis. In: Journal of the American Chemical Society, Vol. 138, No. 6: pp. 1860-1867

Abstract

A sol-gel method for the synthesis of semiconducting FeCrAl oxide photocathodes for solar-driven hydrogen production was developed and applied for the production of meso- and macroporous layers with the overall stoichiometry Fe0.84Cr1.0Al0.16O3. Using transmission electron microscopy and energy-dispersive X-ray spectroscopy, phase separation into Fe- and Cr-rich phases was observed for both morphologies. Compared to prior work and to the mesoporous layer, the macroporous FeCrAl oxide photocathode had a significantly enhanced photo electrolysis performance, even at a very early onset potential of 1.1 V vs RHE. By optimizing the macroporous electrodes, the device reached current densities of up to 0.68 mA cm(-2) at 0.5 V vs RHE under AM 1.5 with an incident photon-to-cur-rent efficiency (IPCE) of 28% at 400 nm without the use of catalysts. Based on transient measurements, this performance increase could be attributed to an improved collection efficiency. At a potential of 0.75 V vs RHE, an electron transfer efficiency of 48.5% was determined.

• Item Type: Journal article
• Faculties: Chemistry and Pharmacy > Department of Chemistry
• Subjects: 500 Science > 540 Chemistry
• ISSN: 0002-7863
• Language: English