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Reaction-diffusion processes for the growth of patterned structures and architectures: A bottom-up approach for photoelectrochemical electrodes

English title Reaction-diffusion processes for the growth of patterned structures and architectures: A bottom-up approach for photoelectrochemical electrodes
Applicant Braun Artur
Number 137868
Funding scheme Project funding (Div. I-III)
Research institution Labor für Hochleistungskeramik EMPA
Institution of higher education Swiss Federal Laboratories for Materials Science and Technology - EMPA
Main discipline Physical Chemistry
Start/End 01.03.2012 - 28.02.2015
Approved amount 317'933.00
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All Disciplines (3)

Discipline
Physical Chemistry
Material Sciences
Microelectronics. Optoelectronics

Keywords (6)

self assembly; pattern formation; photo-electrodes; Liesegang pattern; Reaction-Diffusion; Reaction-Diffusion-Precipitation

Lay Summary (German)

Lead
Strukturbildung findet in der Natur zunächst "von innen heraus" statt. Es sind intrinsische physikalische und chenmische, auch biologische Prozesse, die den Gegenständen und Lebewesen in der Natur ihre Form geben. In der Technik wird den Materialien von aussen durch Werkzeuge ihre Form aufgeprägt. In der Mikro- und Nanotechnologie ist das zusehends schwieriger und aufwendiger. In diesem Projekt wird versucht, in der Natur bekannte Formgebungsprozesse auf mikroskopishcer und molekularer Skala zu verstehen und diese kontrolliert für die Formbildung in der Nanotechnologie nutzen zu können. Die dabei massgebenden elementaren Prozesse sind chemische Reaktionen, Diffusion von Ionen und Niederschlagsbildung.
Lay summary
Strukturbildung findet in der Natur zunächst "von innen heraus" statt. Es sind intrinsische physikalische und chenmische, auch biologische Prozesse, die den Gegenständen und Lebewesen in der Natur ihre Form geben. In der Technik wird den Materialien von aussen durch Werkzeuge ihre Form aufgeprägt. In der Mikro- und Nanotechnologie ist das zusehends schwieriger und aufwendiger. In diesem Projekt wird versucht, in der Natur bekannte Formgebungsprozesse auf mikroskopishcer und molekularer Skala zu verstehen und diese kontrolliert für die Formbildung in der Nanotechnologie nutzen zu können. Die dabei massgebenden elementaren Prozesse sind chemische Reaktionen, Diffusion von Ionen und Niederschlagsbildung.
Direct link to Lay Summary Last update: 07.04.2014

Lay Summary (English)

Lead
The objective of this project is to investigate the influence of reaction - diffusion processes for the design of structured and patterned electrode architectures. This will aid the development of strategies for the synthesis of mesostructured and heterogeneous architectures with relevance to energy materials, for example for electrodes in photoelectrochemical cells (PEC) for solar water splitting. This is a joint PhD project for two PhD students at University of Basel and Empa.
Lay summary
The objective of this project is to investigate the influence of reaction – diffusion processes for the design of structured and patterned electrode architectures. This will aid the development of strategies for the synthesis of mesostructured and heterogeneous architectures with relevance to energy materials, for example for electrodes in photoelectrochemical cells (PEC) for solar water splitting. This is a joint PhD project for two PhD students at University of Basel and Empa.
Solar energy driven splitting of H2O by heterogeneous photocatalysts is a promising green technology for hydrogen fuel production and can be obtained in a single step process in PEC, for which two basic materials criteria must be met: the light harvesting system must have the proper thermodynamics and energetics to effect the decomposition of water, and the system must be corrosion stable in the electrolyte environment. Conventional semiconductor metal oxide catalysts partially possess suitable redox potentials for efficient water splitting. Tuning of the band gap energy is important for the performance of an electrode, but device architecture too plays a crucial role and is increasingly taking centre stage. p-n heterojunctions with pillar architecture can perform better than planar electrodes under certain conditions. Therefore, adding structure to the material is of great interest. Downsizing the structures is also important because nanostructures can offer a very high catalytically active surface area and thus enhanced efficiency. In the extreme case, downsizing may lead to quantum confinement phenomena.
The conventional methods to nanostructure materials are the so called 'top-down' techniques, where structures are produced by fabricating the material by removing parts of it, i.e. lithography methods. Recently considerable attention has been devoted to the so called ‘bottom-up’ techniques where the structure is built from building blocks using self-assembling techniques. Reaction-diffusion-precipitation processes are very promising candidates for building complex structures because the location of the self-organised chemical pattern is locked once it is formed. In the well-known periodic Liesegang pattern (LP), colloidal precipitates form periodically behind a moving reaction front, obeying systematic scaling rules [Liesegang 1896].
We propose the combination of reaction-diffusion processes such as Liesegang phenomena with nanostructuring techniques, for example wet stamping method (PhD student at Basel) or using EHD instability as a driving force (PhD student at Empa) to structure the selected material containing mixed metal ions or nanoparticles.  
The PhD student at University of Basel will synthesise, analyse and understand mixed metal reaction-diffusion planar meso- and/or microstructures and transfer them to ceramic systems. Structural and morphological characterization of the patterns with XRD and Microscopy as well as electrochemical characterisation will be carried out. The photoelectrochemical response of the produced electrodes will be compared with conventional non-structured systems. With the experimental data obtained, we will formulate a model which explains the observed changes in performance as a function of geometrical /topological /morphological peculiarities.
The PhD student at Empa will synthesise an array of radial p-n junction nanopillar cell by using EHD lithography with bilayer of polymer/nanoparticle nanocomposite or bilayer sol-gel chemistry. Structural and morphological characterization will be carried out. The photoelectrochemical activity of planar and pillar array electrodes will be compared, explained and implemented in a demonstrator-type device cell.
The quantum mechanical and thermodynamic properties, which are insignificant in larger, everyday materials, cause nanomaterials to display new and interesting properties. We intend to comprehend properties and exploit them for energy applications. 
Direct link to Lay Summary Last update: 07.04.2014

Responsible applicant and co-applicants

Employees

Publications

Publication
Marangoni Flow Driven Maze Solving
Kohta Suzuno Daishin Ueyama Michal Branicki Rita Tóth Artur Braun István Lagzi (2016), Marangoni Flow Driven Maze Solving, in Andrew Adamatzky (ed.), Springer, Springer International Publishing Switzerland, 237-243.
Probing the mystery of Liesegang band formation: revealing the origin of self-organized dual - frequency micro and nanoparticle arrays
R. Toth R.M. Walliser I. Lagzi F. Boudoire M. Düggelin A. Braun C. E. Housecroft E.C. Const (2016), Probing the mystery of Liesegang band formation: revealing the origin of self-organized dual - frequency micro and nanoparticle arrays, in Soft Matter, 12, 8367-8374.
Understanding the formation of aligned, linear arrays of Ag nanoparticles
R. M. Walliser R. Tóth I. Lagzi D. Mathys L. Marot A. Braun C. E. Housecroft E. C. Constable (2016), Understanding the formation of aligned, linear arrays of Ag nanoparticles, in RSC Advances, 6, 28388-28392.
Maze Solving Using Fatty Acid Chemistry
Suzuno Kohta , Ueyama Daishin, Branicki Michal, Tóth Rita, Braun Artur, Lagzi István (2014), Maze Solving Using Fatty Acid Chemistry, in Langmuir, 30(31), 9251-9255.
A self-assembled, multicomponent water oxidation device
Toth Rita, Walliser Roche M., , A self-assembled, multicomponent water oxidation device, in Chemical Communications.
Hematite nanostructuring using electrohydrodynamic lithography
Boudoire Florent, Hematite nanostructuring using electrohydrodynamic lithography, in Applied Surface Science.
Molecular Origin and Electrochemical Influence of Capacitive Surface States on Iron Oxide Photoanodes
Hu Yelin, Molecular Origin and Electrochemical Influence of Capacitive Surface States on Iron Oxide Photoanodes, in Journal of Physical Chemistry C.
Photonic light trapping in self-organized all-oxide microspheroids impacts photoelectrochemical water splitting
Florent Boudoire Rita Toth Jakob Heier Artur Braun Edwin C. Constable, Photonic light trapping in self-organized all-oxide microspheroids impacts photoelectrochemical water splitting, in Energy & Environmental Science.

Collaboration

Group / person Country
Types of collaboration
Univ. of Pretoria South Africa (Africa)
- in-depth/constructive exchanges on approaches, methods or results
Helmholtz Zentrum Berlin BESSY-II Germany (Europe)
- Research Infrastructure
Prof. Moser Group, EPFL Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
- Exchange of personnel
Fachhochschule Vorarlberg Institut fuer Mikrotechnologie Austria (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure
- Industry/business/other use-inspired collaboration
Swiss Light Source Switzerland (Europe)
- Publication
- Research Infrastructure
Graetzel Group Switzerland (Europe)
- Publication
- Research Infrastructure
- Exchange of personnel
Istvan Lagzy Hungary (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
- Research Infrastructure
- Exchange of personnel

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
20th International Conference on Conversion and Storage of Solar Energy (IPS20) Talk given at a conference Self-organized Micron-scale Architectures for Photonic Visible Light Trapping in Metal Oxide Water Splitting Photoanodes 29.07.2014 Berlin, Germany Boudoire Florent;
E-MRS, Symposium I: Solution Processing and Properties of Functional Oxide Thin Films and Nanostructures Talk given at a conference Impact of Photonic Light Trapping on Photoelectrochemical Water Splitting in Hematite-coated mWO3 Microspheroids 30.05.2014 Lille, France Boudoire Florent;
Swiss Nanoconvention 2014 Poster Light Management in Nanostructured Water Splitting Photoanodes 21.05.2014 Brugg Windisch, Switzerland Boudoire Florent;
MRS, Symposium F: Controlling the interaction between Light and Semiconductor Nanostructures for Energy Applications Poster Visible Light Trapping in Microstructured Oxide Photoanodes for Solar Water Splitting 24.04.2014 San Francisco, United States of America Boudoire Florent;
US DoE PEC Working Group and Annex 26 IEA HIA Annual Meeting Talk given at a conference Photonic Light Management for PEC Electrodes 21.04.2014 Stanford University, United States of America Braun Artur; Boudoire Florent;
2nd Clariant Chemistry Day, University of Basel Talk given at a conference "Green Energy" by solar water splitting" 09.04.2014 Basel, Switzerland Walliser Roche Marcel;
Chemistry Department Seminar at University of Pretoria Individual talk Self-organized Micron-scale Architectures for Photonic Visible Light Trapping in Metal Oxide Water Splitting Photoanodes 14.03.2014 Pretoria, South Africa Boudoire Florent;
iTHEMBA Labs Seminar Individual talk Self-organized Micron-scale Architectures for Photonic Visible Light Trapping in Metal Oxide Water Splitting Photoanodes 10.03.2014 Somerset, South Africa Boudoire Florent;
30th Annual Meeting of the Swiss Working Group on Surface and Interface Science Poster Impact of photonic light-trapping on photoelectrochemical water splitting in hematite coated mWO3 microspheroids 24.01.2014 Fribourg, Switzerland Boudoire Florent;
Empa PhD Students' Symposium 2013 Talk given at a conference Visible light trapping in microstructured oxide photoanodes for solar water splitting 23.10.2013 Empa, Dübendorf, Switzerland Boudoire Florent;
Green Energy am SCS Fallmeeting 2013 EPF Lausanne Talk given at a conference Green Energy by solar water splitting 13.09.2013 Lausanne, Switzerland Walliser Roche Marcel;
20th EuCheMS Conference on organometallic chemistry Poster Green Energy by solar watersplitting 21.07.2013 St. Andrews, Great Britain and Northern Ireland Walliser Roche Marcel;
Swiss Nanoconvention 2013 Poster Efficient light trapping on patterned oxide photoanode surface for application in water splitting 23.05.2013 Basel, Switzerland Boudoire Florent;
Workshop on Patterns and Hydrodynamic Instabilities in Reactive Systems Poster Hematite nanopatterning using electrohydrodynamic lithography 14.05.2013 Brussels, Belgium Boudoire Florent;
29th Annual Meeting of the Swiss Working Group for Surface and Interface Science Poster From polymers to oxides: A novel bottom-up approach to grow hematite sub-micro and nanostructures 25.01.2013 Fribourg, Switzerland Boudoire Florent;
1st Clariant Chemistry Day, University of Basel Poster Green Energy by solar water splitting 15.11.2012 Basel, Switzerland Walliser Roche Marcel;
Empa PhD Students' Symposium 2012 Talk given at a conference From polymers to oxides: A novel bottom-up approach to grow hematite sub-micro and nanostructures 13.11.2012 Dübendorf, Switzerland Boudoire Florent;
Empa Evaluierungsbesuch durch Internationale Forschungskommission C Poster From polymers to oxides: A novel bottom-up approach to grow hematite sub-micro and nanostructures 07.11.2012 Dübendorf, Switzerland Boudoire Florent;
Summer School on Bio-medical Imaging Poster Self Organization 03.09.2012 Zürich Center for Imaging Science and Technology CIMST, Switzerland Boudoire Florent;


Knowledge transfer events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
Designers' open 2012 Performances, exhibitions (e.g. for education institutions) 26.10.2012 Leipzig, Germany


Communication with the public

Communication Title Media Place Year
Media relations: print media, online media Geschäftsbericht des ETH-Rats über den ETH-Bereich ETH-Rat International German-speaking Switzerland Italian-speaking Switzerland Western Switzerland Rhaeto-Romanic Switzerland 2015
Media relations: print media, online media Zufall und Übermut (Editorial) megalink German-speaking Switzerland 2015
Media relations: print media, online media Ein Navi aus dem Chemielabor Zürcher Oberländer German-speaking Switzerland 2014
Media relations: print media, online media A GPS from the chemistry set Science Daily International 2014
Media relations: print media, online media Chemie-Navi: Mit Säure zur PizzeriaDiese Entdeckung könnte das Navigationssystem revolutionieren FOCUS 46/14, 10 November 2014, Seite 112 International 2014
Media relations: print media, online media Collecting light with artificial moth eyes Empa News International Italian-speaking Switzerland German-speaking Switzerland Western Switzerland Rhaeto-Romanic Switzerland 2014
Media relations: print media, online media De l'hydrogène produit avec un oeil de mite artificiel Le Monde, 23 June 2014 International 2014
Media relations: radio, television Des petites bêtes alliées de la science RSR, La Première, CQFD Western Switzerland International 2014
Media relations: print media, online media Ein Navi aus dem Chemielabor MyScience.ch Western Switzerland German-speaking Switzerland Rhaeto-Romanic Switzerland Italian-speaking Switzerland 2014
Media relations: print media, online media Künstliches Mottenauge als Lichtfänger Empa News Jahrgang 13, Nummer 45, Juli 2014, 10-11. German-speaking Switzerland 2014
Media relations: print media, online media L’oeil de mite, un piège à lumière La Liberté Western Switzerland 2014
Media relations: print media, online media Moleküle finden den kürzesten Weg Technology Review - Das Magazin für Innovation, 12/2014, Seite 16 International 2014
New media (web, blogs, podcasts, news feeds etc.) Moth Eyes Inspire Different Solar Cell Scientific American International 2014
New media (web, blogs, podcasts, news feeds etc.) Photoelectrochemical Water Splitting Can Be Achieved with Self-Organized, All-Oxide Electrodes materials360 online International 2014
Media relations: radio, television Radiointerview mit Istvan Lagzi (Uni Budapest) Deutschlandradio International 2014
Media relations: print media, online media Tiny balls of fire: How to gather more light for solar power The Economist International 2014
Other activities Webpage: Photonic light trapping for photoelectrochemical water splitting Italian-speaking Switzerland Western Switzerland International German-speaking Switzerland Rhaeto-Romanic Switzerland 2014

Awards

Title Year
European Materials Research Society Young Scientist Award presented to Florent Boudoire in recognition of an outstanding paper contributed to the 2014 E-MRS Spring Meeting Symposium I: Solution Processing and Properties of Functional Oxide Thin Films and Nanostructures. 2014
Florent Boudoire, Artur Braun, Edwin C. Constable, Jakob Heier and Rita Toth (MHV Fellow) have been listed as "Foreign Policy’s 100 Leading Global Thinkers of 2014". The editors of Foreign Policy chose them based on "their standout contributions over the past year and their ability to translate important ideas into action that change and shape the world". 2014
3rd Place Oral Presentation Award at Empa PhD Students' Symposium 2013 2013
1st Place Oral Presentation Award at Empa PhD Students' Symposium 2012 2012

Associated projects

Number Title Start Funding scheme
121306 Fundamental Aspects of Photocatalysis and Photoelectrochemistry / Basic Research Instrumentation for Functional Characterization 01.07.2008 R'EQUIP
132126 Defects in the bulk and on surfaces and interfaces of metal oxides with photoelectrochemical properties: In-situ photoelectrochemical and resonant x-ray and electron spectroscopy studies 01.06.2011 Project funding (Div. I-III)
133944 Oxide heterointerfaces in assemblies for photoelectrochemical applications 01.11.2010 International short research visits
149031 Production of Liquid Solar Fuels from CO2 and Water: Using Renewable Energy Resources 01.03.2014 Bilateral programmes
139698 Self-organization processes to pattern thin films: A bottom-up approach for photoelectrodes 01.02.2012 Marie Heim-Voegtlin grants
162232 SNF Korean Swiss project: Molecular and physical aspects of dye sensitization of photoelec-trodes with copper-based sensitizer molecules 01.02.2016 Bilateral programmes
160116 Morphology control by ionic interactions of cyanine / PCBM bulk heterojunctions for photovoltaic applications 01.08.2015 Project funding (Div. I-III)

Abstract

The objective of this project is to investigate the influence of reaction - diffusion processes for the design of structured and patterned electrode architectures. This will aid the development of strategies for the synthesis of mesostructured and heterogeneous architectures with relevance to energy materials, for example for electrodes in photoelectrochemical cells (PEC) for solar water splitting. This is a joint PhD project for two PhD students at University of Basel and Empa.Solar energy driven splitting of H2O by heterogeneous photocatalysts is a promising green technology for hydrogen fuel production and can be obtained in a single step process in PEC, for which two basic materials criteria must be met: the light harvesting system must have the proper thermodynamics and energetics to effect the decomposition of water, and the system must be corrosion stable in the electrolyte environment. Conventional semiconductor metal oxide catalysts partially possess suitable redox potentials for efficient water splitting. Tuning of the band gap energy is important for the performance of an electrode, but device architecture too plays a crucial role and is increasingly taking centre stage. p-n heterojunctions with pillar architecture can perform better than planar electrodes under certain conditions. Therefore, adding structure to the material is of great interest. Downsizing the structures is also important because nanostructures can offer a very high catalytically active surface area and thus enhanced efficiency. In the extreme case, downsizing may lead to quantum confinement phenomena.The conventional methods to nanostructure materials are the so called 'top-down' techniques, where structures are produced by fabricating the material by removing parts of it, i.e. lithography methods. Recently considerable attention has been devoted to the so called ‘bottom-up’ techniques where the structure is built from building blocks using self-assembling techniques. Reaction-diffusion-precipitation processes are very promising candidates for building complex structures because the location of the self-organised chemical pattern is locked once it is formed. In the well-known periodic Liesegang pattern (LP), colloidal precipitates form periodically behind a moving reaction front, obeying systematic scaling rules [Liesegang 1896].We propose the combination of reaction-diffusion processes such as Liesegang phenomena with nanostructuring techniques, for example wet stamping method (PhD student at Basel) or using EHD instability as a driving force (PhD student at Empa) to structure the selected material containing mixed metal ions or nanoparticles. The PhD student at University of Basel will synthesise, analyse and understand mixed metal reaction-diffusion planar meso- and/or microstructures and transfer them to ceramic systems. Structural and morphological characterization of the patterns with XRD and Microscopy as well as electrochemical characterisation will be carried out. The photoelectrochemical response of the produced electrodes will be compared with conventional non-structured systems. With the experimental data obtained, we will formulate a model which explains the observed changes in performance as a function of geometrical /topological /morphological peculiarities. The PhD student at Empa will synthesise an array of radial p-n junction nanopillar cell by using EHD lithography with bilayer of polymer/nanoparticle nanocomposite or bilayer sol-gel chemistry. Structural and morphological characterization will be carried out. The photoelectrochemical activity of planar and pillar array electrodes will be compared, explained and implemented in a demonstrator-type device cell. The quantum mechanical and thermodynamic properties, which are insignificant in larger, everyday materials, cause nanomaterials to display new and interesting properties. We intend to comprehend properties and exploit them for energy applications.
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