TY - JOUR

T1 - Enhanced Oxygen Evolution Reaction Activity of Nanoporous SnO 2 /Fe 2 O 3 /IrO 2 Thin Film Composite Electrodes with Ultralow Noble Metal Loading

AU - Haschke, Sandra

AU - Zhuo, Ying

AU - Schlicht, Stefanie

AU - Barr, Maïssa K.S.

AU - Kloth, Ricarda

AU - Dufond, Maxime E.

AU - Santinacci, Lionel

AU - Bachmann, Julien

N1 - Publisher Copyright: © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

PY - 2019/2/8

Y1 - 2019/2/8

N2 - A conductive SnO 2 layer and small quantities of IrO 2 surface cocatalyst enhance the catalytic efficiency of nanoporous Fe 2 O 3 electrodes in the oxygen evolution reaction at neutral pH. Anodic alumina templates are therefore coated with thin layers of SnO 2 , Fe 2 O 3 , and IrO 2 by atomic layer deposition. In the first step, the Fe 2 O 3 electrode is modified with a conductive SnO 2 layer and submitted to different postdeposition thermal treatments in order to maximize its catalytic performance. The combination of steady-state electrolysis, electrochemical impedance spectroscopy, X-ray crystallography, and X-ray photoelectron spectroscopy demonstrates that catalytic turnover and e − extraction are most efficient if both layers are amorphous in nature. In the second step, small quantities of IrO 2 with extremely low iridium loading of 7.5 µg cm −2 are coated on the electrode surface. These electrodes reveal favorable long-term stability over at least 15 h and achieve maximized steady-state current densities of 0.57 ± 0.05 mA cm −2 at η = 0.38 V and pH 7 (1.36 ± 0.10 mA cm −2 at η = 0.48 V) in dark conditions. This architecture enables charge carrier separation and reduces the photoelectrochemical water oxidation onset by 300 mV with respect to pure Fe 2 O 3 electrodes of identical geometry.

AB - A conductive SnO 2 layer and small quantities of IrO 2 surface cocatalyst enhance the catalytic efficiency of nanoporous Fe 2 O 3 electrodes in the oxygen evolution reaction at neutral pH. Anodic alumina templates are therefore coated with thin layers of SnO 2 , Fe 2 O 3 , and IrO 2 by atomic layer deposition. In the first step, the Fe 2 O 3 electrode is modified with a conductive SnO 2 layer and submitted to different postdeposition thermal treatments in order to maximize its catalytic performance. The combination of steady-state electrolysis, electrochemical impedance spectroscopy, X-ray crystallography, and X-ray photoelectron spectroscopy demonstrates that catalytic turnover and e − extraction are most efficient if both layers are amorphous in nature. In the second step, small quantities of IrO 2 with extremely low iridium loading of 7.5 µg cm −2 are coated on the electrode surface. These electrodes reveal favorable long-term stability over at least 15 h and achieve maximized steady-state current densities of 0.57 ± 0.05 mA cm −2 at η = 0.38 V and pH 7 (1.36 ± 0.10 mA cm −2 at η = 0.48 V) in dark conditions. This architecture enables charge carrier separation and reduces the photoelectrochemical water oxidation onset by 300 mV with respect to pure Fe 2 O 3 electrodes of identical geometry.

KW - atomic layer deposition

KW - iridium oxide

KW - iron oxide

KW - nanostructures

KW - water splitting

UR - http://www.scopus.com/inward/record.url?scp=85058040799&partnerID=8YFLogxK

U2 - 10.1002/admi.201801432

DO - 10.1002/admi.201801432

M3 - Article

VL - 6

SP - 1801432

JO - Advanced Materials Interfaces

JF - Advanced Materials Interfaces

SN - 2196-7350

IS - 3

M1 - 1801432

ER -