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Flanders/Swiss Lead Agency Process: Charge and energy transfer between cyanobacteria and semiconductor electrodes under gamma-irradiation

English title Flanders/Swiss Lead Agency Process: Charge and energy transfer between cyanobacteria and semiconductor electrodes under gamma-irradiation
Applicant Braun Artur
Number 189455
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 Other disciplines of Physics
Start/End 01.10.2020 - 30.09.2024
Approved amount 446'800.00
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All Disciplines (2)

Discipline
Other disciplines of Physics
Biophysics

Keywords (7)

Gamma-rays; Radiation damage; Flanders; Photosynthesis; Cyanobacteria; Algae; Photoelectrochemistry

Lay Summary (German)

Lead
Cyanobakterien gehören zu den frühesten und primitven Formen des Lebens und eignen sich damit gut für grundsätzliche Untersuchungen zu deren Lebensfähigkeit unter extremen Bedingungen, wie etwa im Weltraum, wo sie für künftige Kolonisation als Nahruzngsquelle dienen könnten. Eine andere Anwendung ist die Funktionalisierung mit Halbleiteroberflächen als Photoelektroden für die solar Wasserspaltung für solaren Wasserstoff als Speicherbrennstoff. Im Weltraum wären Cyanobakterien einer erheblichen Belastung durch Protonen und andere Strahlen ausgesetzt. Wir untersuchen die Wechselwirkung von Cyanobakterien mit Gammastrahlen, indem wir sie auf Photoelektroden aufbringen. Es handelt sich hier um ein Kollaborationsprojekt mit dem Kernforschungszentrum in Mol und der Universität Hasselt in Belgien.
Lay summary
Im einzelnen werden wir die Haftung der Cyanobakterien auf Elektroden untersuchen, die aus mit dem Element Bor gedopten Diamantfilmen bestehen. Mit elektroanalytischen Methoden werden wir die elektrische Ladungsträgerdynamik dieser Biohybrid-Elektroden bei Dunkelheit und bei Belichtung untersuchen, wobei wir verschiedene Dosen von Gammastrahlung auf die Elektroden richten - und damit die Versagensmechanismen des photosynthetischen Apparats aufzuklären versuchen. Unterstützt werden die Untersuchungen mit Synchrotronstrahlung, insbesondere resonante Photoemission under "ambient pressure conditions", wo die elektrifizierten Biofilme unter elektrophysiologischen Bedingungen gemessen und elementspezifische Valenzbandspektren aufgenommen werden. Damit sollten wesentliche Erkenntnissse über die molekularen Ursachen und Mechanismen der Pathogenese des photosynthetischen Apparates gewonne werden.
Direct link to Lay Summary Last update: 12.03.2020

Responsible applicant and co-applicants

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Associated projects

Number Title Start Funding scheme
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)
121306 Fundamental Aspects of Photocatalysis and Photoelectrochemistry / Basic Research Instrumentation for Functional Characterization 01.07.2008 R'EQUIP
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
161673 International Exploratory Workshop on Photoelectrochemistry, Catalysis and X-ray spectroscopy 01.07.2015 International Exploratory Workshops
175249 Electrochemistry of the thylakoid membrane - metal oxide electrode assemblies 01.08.2017 International short research visits

Abstract

We will investigate the impact of ionizing gamma-radiation on the photosynthetic apparatus of cyanobacteria, some of which are considered for biological life support systems in future space stations and outer space and deployable in a range of other space applications such as mineral mining and terraformation. Cyanobacteria and other phototrophs can also be used for energy harvesting and solar fuel production in photoelectrochemcial reactors, the surfaces of which are functionalized with living cells and/or their components. However, ionizing radiation (e.g. gamma-radiation) is prevalent in the space environment and is very harmful to biological systems because it causes direct or indirect damage to all cell components. We will study the vulnerability and sustainability of immobilized cyanobacteria or their conjugated biological components during gamma-radiation with electroanalytical and spectroscopic methods.The conventional application of the intrinsically highly inefficient process of natural photosynthesis is the conversion of solar energy into edible biomass. In the last century researchers have tried to mimic and synthetically improve this life-bearing process for various purposes, most notably for direct energy conversion technologies. Historically, research paths took a split development into photovoltaics (PV) for electricity production, semiconductor photoelectrochemistry for fuel production in photoelectrochemical cells (PECs), and artificial photosynthesis (AP), as the only bio-organic path. Algae and bacteria have been studied in bio-hybrid photoelectrochemical systems and in bio fuel cells.PV is a scientifically well-explored field, which has produced a market-ready technology for electric energy and power production having a potential impact on the energy economy in many countries worldwide. Although PV can only produce electricity and no biofuels it can be combined with water electrolyzers and then produce hydrogen, which can be stored until use at H2 gas stations.For the past 10 years there has been an enormous interest in using the principle of PECs for solar hydrogen and fuel production. This is an integrated approach, which is believed to be commercially more efficient than a PV-based solution, once all technological bottlenecks are successfully addressed.Biological photosynthesis has been explored in parallel to PEC and PV. Bioreactors have been developed, which produce solar hydrogen or hydrocarbons [Liu 2015b]. There has been more emphasis on understanding the fundamental biochemical and biophysical principles and not so much progress in making devices and reactors. The reason for this is that photosynthesis applications require a top-down and reductionist approach in which the working principles at the molecular scale must be first successfully explored.A hybrid approach uses components from the photosynthetic apparatus, such as hydrogenase, oxygenase, phycocyanin or bacteriorhodopsin, or complete cells, which are attached to electrodes. Our project deals with this hybrid approach. It is therefore important to put the electric properties of this heterostructure from bio-organic components, semiconductor photoelectrode or current collector electrode and their mutual interfaces in the right electric context.All approaches share in common that they are powered by light, i.e. by solar radiation. The solar spectrum extends from high energy y-radiation to the far infrared with low energy quanta. Only the narrow wavelength range of visible light is actually utilized for the energy conversion. The high energy of the ultraviolet photons can cause damage to materials and molecules by direct interaction with the matter or by secondary generation of radicals from air molecules (H2O; O2; N2) which chemically attach to the PV and PEC materials or bio-organic molecules.The very high energy UVC rays, X-rays and y-rays are shielded from arriving at the Earth surface by the geomagnetic field of the Earth and via interaction with gas molecules (e.g., ozone) in the ionosphere. The biophysical spheres around the globe together with the Earth’s geomagnetic field thus efficiently protect the natural photosynthesis apparatus and also any synthetic or bio-hybrid photon-based energy conversion system from the most severe damages (although at high altitudes and at the poles solar radiation is less blocked, more intense and hence likely more harmful).In space and outer space, there is no such protection except perhaps for man-made sophisticated shielding at the space station or spaceship. But shielding always will come at a cost of weight which for space exploration remains a crucial factor, hence space organizations are envisaging so-called waterwalls integrated with cyanobacterial life-support reactors. Exposure to cosmic radiation and gamma-radiation can influence the function and integrity of the photosynthetic apparatus. Semiconductors become also influenced by radiation.The major question that arises is: to what extent do photons of gamma rays interfere with natural or artificial photosynthesis and under what conditions of attenuation and dissipation could such photons energetically drive or support biological or semi-biological systems without causing detrimental damage? We will study the photosynthesis performance of semiconductor photoelectrodes, which are functionalized with cyanobacteria in photo-electrophysiological conditions while under irradiation with gamma-rays. We employ the cyanobacteria as bio-electrodes for two reasons. On one hand, electroanalytical methods are well suited for the assessment of photosynthesis functions.
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