Header

UZH-Logo

Maintenance Infos

Photochemical and electrocatalytic water oxidation activity of cobalt carbodiimide


Ressnig, Debora; Shalom, Menny; Patscheider, Jörg; Moré, René; Evangelisti, Fabio; Antonietti, Markus; Patzke, Greta R (2015). Photochemical and electrocatalytic water oxidation activity of cobalt carbodiimide. Journal of Materials Chemistry A, 3(9):5072-5082.

Abstract

Cobalt carbodiimide is introduced as a heterogeneous non-oxidic water oxidation catalyst prototype with dual photochemical and electrocatalytic activity in neutral and basic media. CoNCN exhibits higher initial turnover frequencies of (TOF/SBET: 2.1 × 10−1) for visible-light-driven oxygen evolution than cobalt oxide catalysts (TOF/SBET: 3.5 × 10−3) and a 18% higher oxygen yield (Ru-dye sensitized standard setup). Furthermore, CoNCN maintains stable current densities in electrolysis over 20 h, and structural tuning through cationic substitution revealed that mixed (Co, Ni)NCN catalysts with low Ni contents display higher current densities than pristine CoNCN. A wide range of bulk (XAFS/EXAFS, XRD, FTIR) and surface (XPS, EELS, HRTEM) analytical methods together with catalytic parameter variations and reference experiments were performed to confirm the stability of CoNCN under standard operational conditions. The carbodiimide matrix thus offers a straightforward structural alternative to oxide systems and a clear-cut starting point for optimization strategies and for mechanistic studies on the possible role of active carbon or nitrogen sites. This paves the way to metal carbodiimides as a novel catalyst design platform for heterogeneous energy conversion systems.

Abstract

Cobalt carbodiimide is introduced as a heterogeneous non-oxidic water oxidation catalyst prototype with dual photochemical and electrocatalytic activity in neutral and basic media. CoNCN exhibits higher initial turnover frequencies of (TOF/SBET: 2.1 × 10−1) for visible-light-driven oxygen evolution than cobalt oxide catalysts (TOF/SBET: 3.5 × 10−3) and a 18% higher oxygen yield (Ru-dye sensitized standard setup). Furthermore, CoNCN maintains stable current densities in electrolysis over 20 h, and structural tuning through cationic substitution revealed that mixed (Co, Ni)NCN catalysts with low Ni contents display higher current densities than pristine CoNCN. A wide range of bulk (XAFS/EXAFS, XRD, FTIR) and surface (XPS, EELS, HRTEM) analytical methods together with catalytic parameter variations and reference experiments were performed to confirm the stability of CoNCN under standard operational conditions. The carbodiimide matrix thus offers a straightforward structural alternative to oxide systems and a clear-cut starting point for optimization strategies and for mechanistic studies on the possible role of active carbon or nitrogen sites. This paves the way to metal carbodiimides as a novel catalyst design platform for heterogeneous energy conversion systems.

Statistics

Citations

13 citations in Web of Science®
14 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

38 downloads since deposited on 18 Jan 2016
25 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:07 Faculty of Science > Department of Chemistry
Dewey Decimal Classification:540 Chemistry
Language:English
Date:7 March 2015
Deposited On:18 Jan 2016 15:55
Last Modified:27 May 2017 07:20
Publisher:Royal Society of Chemistry
ISSN:2050-7488
Free access at:Publisher DOI. An embargo period may apply.
Publisher DOI:https://doi.org/10.1039/C5TA00369E

Download

Download PDF  'Photochemical and electrocatalytic water oxidation activity of cobalt carbodiimide'.
Preview
Content: Published Version
Filetype: PDF
Size: 1MB
View at publisher
Licence: Creative Commons: Attribution 3.0 Unported (CC BY 3.0)