Projects and cooperations

Metaloxid-4-Hydrogen

Name of project:
Complex metal oxide as efficient and stable components for solar hydrogen production (Metalloxid-4-Hydrogen)

Funding agency:
BMBF

Duration:
2014-2018

Project leader:
Prof. Dr. Roel van de Krol

Partners involved:
Prof. Dr. Catherine Dubourdieu (HZB EM-IFOX); Prof. Elke Wendler (Friedrich-Schiller-Universität Jena); Prof. Dr. Harry Tuller (Massachusetts Institute of Technology)

Abstract:
Metal oxides are promising materials for efficient photoelectrodes in solar hydrogen production due to their general aqueous stability and low cost. However, the development of binary metal oxides thus far has not resulted in adequate efficiency. In this project, we explore complex metal oxides (i.e., ternary, quaternary) as the photoelectrode materials. Emphasis is placed on the determination of the performance limiting factors and control over intrinsic / extrinsic defects. Promising complex metal oxides are then utilized as the top absorbers to be combined with a nanostructured silicon electrode bottom absorber, in order to fabricate an efficient tandem device for solar hydrogen generation.

No. of dedicated PhD/postdocs:
4 PhD students

Highlights:
F. Wang, W. Septina, A. Chemseddine, F. F. Abdi, D. Friedrich, P. Bogdanoff, R. van de Krol, S. D. Tilley, S. P. Berglund
Gradiend Self-Doped CuBi2O4 with Highly Improved Charge Separation Efficiency, Journal of the American Chemical Society, 2017, in press

W. Jang, D. Friedrich, S. Müller, M. Lamers, H. Hempel, S. Lardhi, Z. Cao, M. Harb, L. Cavallo, R. Heller, R. Eichberger, R. van de Krol, F.F. Abdi
Enhancing charge carrier lifetime in metal oxide photoelectrodes through mild hydrogen treatment, Advanced Energy Materials, 2017, in press

F. Wang, A. Chemseddine, F. F. Abdi, R. van de Krol, S. P. Berglund
Spray Pyrolysis of CuBi2O4Photocathodes: Improved Solution Chemistry for Highly Homogeneous Thin FilmsJournal of Materials Chemistry A, 5, 2017, 12838-12847

F. Abdi, S. P. Berglund
Recent Developments in Complex Metal Oxide PhotoelectrodesJournal of Physics D: Applied Physics, 50, 2017, 193002

F. Abdi, A. Chemseddine, S.P. Berglund, R. van de Krol
Assessing the suitability of iron tungstate (Fe2WO6) as a photoelectrode material for water oxidation, Journal of Physical Chemistry C 121, 153-160 (2017)

M. Ziwritsch, S. Müller, H. Hempel, T. Unold, F.F. Abdi, R. van de Krol, D. Friedrich, R. Eichberger
Direct time-resolved observation of carrier trapping and polaron conductivity in BiVO4, ACS Energy Letters, 1, 888-894 (2016)

P. Berglund, F.F. Abdi, P. Bogdanoff, A. Chemseddine, D. Friedrich, R. van de Krol,
Comprehensive Evaluation of CuBi2O4 as a Photocathode Material for Photoelectrochemical Water Splitting, Chemistry of Materials, 28, 4231-4242 (2016)


MANGAN

Name of Project:
Manganese and cobalt oxide catalysts for water oxidation: thin film model system and efficient coupling on metal oxide photoelectrodes.
(Subproject of the cluster-project “MANGAN”)

Funding agency:
BMBF

Duration:
05/2015- 04/2019

Project leader:
Prof. Dr. Roel van de Krol

Partners involved:
MANGAN comprises 15 sub projects and 25 research groups from Fritz Haber Institute of the Max Planck Society, Helmholtz-Zentrum Berlin, Max Planck Institutes for Iron Reasearch and for Chemical Energy Conversion, the Technical Universities of Aachen, Berlin, and Darmstadt, as well as the universities of Bochum, Duisburg-Essen, Erlangen-Nürnberg, Freiburg, Gießen, and Mainz and one partner from the industry.

Abstract:
The generation of hydrogen from electrochemical splitting of water, electrolysis, is without doubt one of the key technologies in a sustainable energy scenario. The technical application is, however, still hampered by e.g. the high cost of electrocatalysts based on noble metals. There is, hence, a considerable effort undertaken to replace these catalysts with lower-cost catalysts based on earth-abundant materials such as iron, carbon, or manganese.
The MANGAN clusterproject is dealing with manganese-based compounds as electrocatalysts for electrochemical water splitting. The aim of the project is not so much a device but to understand the fundamentals of electrochemical water splitting by manganese-based catalysts in various formulations. The underlying structure-function relationships play a central role in this endeavor. The question that the MANGAN project seeks to answer is whether and, if so, under which boundary conditions manganese-based compounds might have the potential to replace existing but pricey water splitting catalysts on the basis of noble metals.
The expertise of the project partners includes synthesis of diverse manganese-based compounds such as well-defined manganese oxides or manganese-impregnated carbon composites, new electrode architectures and substrate materials, fundamental electrochemistry and standardized measurements, high-end spectroscopic techniques and theoretical modelling. Within the HZB-subproject we explore the fundamental limitations of cheap abundant manganese and cobalt oxide electro-catalysts for the water oxidation reaction (electrolysis). Thin film model systems are used in order to quantitatively determine the structure-property relationship. Finally, these catalysts are coupled to semiconducting metal oxide light absorbers in order to form integrated photoelectrochemical anodes. The charge transfer processes at the interfaces during photoelectrochemical water oxidation are investigated in dependence on the electronic structure of the absorbers and the catalysts. These studies are the base for the development of a universal model for the design of efficient photoanodes.

No. of dedicated PhD/postdocs:
2 PhD students


Fundamentals of Electrochemical Interfaces

Name of the project:
Fundamentals of Electrochemical Interfaces: Complex Oxide/Electrolyte Interfaces

Funding agency:
BMBF

Duration:
Jan. 2017 - Dec. 2020

Project leaders:
Prof. Dr. Roel van de Krol, Dr. David Starr
(main proposer: Prof. Jaegermann at the TU-Darmstadt)

Partners involved:
TU-Darmstadt, Universität Ulm, Fritz Haber Institute, MPI CEC-Mülheim

Abstract:
This project focuses on gaining a molecular-level understanding of the interface formed between complex oxide semiconductors and aqueous electrolytes, specifically bismuth vanadate/aqueous electrolyte interfaces. To do so we will use single crystal surfaces of BiVO4 combined with synchrotron-based ambient pressure photoelectron spectroscopy with both soft and hard X-rays. These measurements will be complemented by traditional surface science measurements in ultra-high vacuum including UPS, XPS, LEED, ISS and STM. The goal is a molecular-level correlation between the chemical composition and electronic structure at the interface.

No. of PhD students/Post-docs:
1 post-doc

Highlight:
M. Favaro,* F. F. Abdi, M. Lamers, E. J. Crumlin, Z. Liu, R. van de Krol, D. E. Starr*
Light-induced Surface Reactions at the Bismuth Vanadate/Potassium Phosphate Interface, Journal of Physical Chemistry B, (2017)