TY - JOUR

T1 - Properties, performance and stability of iridium-coated water oxidation electrodes based on anodized titanium felts

AU - Hofer, André

AU - Bochmann, Sebastian

AU - Bachmann, Julien

N1 - Publisher Copyright: © The Royal Society of Chemistry. Copyright: Copyright 2021 Elsevier B.V., All rights reserved.

PY - 2021/1/21

Y1 - 2021/1/21

N2 - This study explores the preparation of porous titanium felts as substrates for water oxidation electrodes. We approach the characterization of their performance in a holistic manner: not just a single performance parameter is considered, but instead a combination of short-term electrocatalytic proficiency in process-relevant conditions and long-term stability. The preparation combines two ingredients: (1) anodization of the felts to generate surface porosity with (2) atomic layer deposition (ALD) to coat the porous substrates with thin iridium films of 8 nm thickness. Samples generated with anodization in various conditions are characterized quantitatively in terms of their electrochemical performance (overpotential η10, maximum current density jmax, electrochemically active surface area expressed as roughness factor rf) and of their stability (electrochemical, chemical and physical). We find that electrodes obtained by anodization in water exhibit both lower stability and lower performance than their counterparts prepared in organic electrolytes. However, the electrode type that exhibits the best pure electrochemical performance (lowest η10 and highest jmax) also exhibits a fragile surface structure. For all samples, the very low catalyst loading on the order of tens of μg cm-2 ensures a significant materials cost reduction with respect to traditional preparative methods. This journal is

AB - This study explores the preparation of porous titanium felts as substrates for water oxidation electrodes. We approach the characterization of their performance in a holistic manner: not just a single performance parameter is considered, but instead a combination of short-term electrocatalytic proficiency in process-relevant conditions and long-term stability. The preparation combines two ingredients: (1) anodization of the felts to generate surface porosity with (2) atomic layer deposition (ALD) to coat the porous substrates with thin iridium films of 8 nm thickness. Samples generated with anodization in various conditions are characterized quantitatively in terms of their electrochemical performance (overpotential η10, maximum current density jmax, electrochemically active surface area expressed as roughness factor rf) and of their stability (electrochemical, chemical and physical). We find that electrodes obtained by anodization in water exhibit both lower stability and lower performance than their counterparts prepared in organic electrolytes. However, the electrode type that exhibits the best pure electrochemical performance (lowest η10 and highest jmax) also exhibits a fragile surface structure. For all samples, the very low catalyst loading on the order of tens of μg cm-2 ensures a significant materials cost reduction with respect to traditional preparative methods. This journal is

KW - ATOMIC LAYER DEPOSITION

KW - OXYGEN EVOLUTION REACTION

KW - SURFACE-AREA

KW - TIO2 NANOTUBES

KW - FABRICATION

KW - ANODIZATION

KW - EFFICIENT

UR - http://www.scopus.com/inward/record.url?scp=85099919895&partnerID=8YFLogxK

U2 - 10.1039/d0se01577f

DO - 10.1039/d0se01577f

M3 - Article

AN - SCOPUS:85099919895

VL - 5

SP - 478

EP - 485

JO - Sustainable Energy and Fuels

JF - Sustainable Energy and Fuels

SN - 2398-4902

IS - 2

ER -