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Dahl, Øystein; Sunding, Martin Fleissner; Thøgersen, Annett; Killi, Veronica Anne-Line Kathrine; Svenum, Ingeborg-Helene & Grandcolas, Mathieu
[Show all 10 contributors for this article]
(2023).
Direct observation of interfacial energetics at Ta3N5/electrolyte and Ta3N5/NiOx/electrolyte heterojunctions by operando ambient pressure X-ray photoelectron spectroscopy during photoelectrochemical water splitting.
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Dahl, Øystein; Sunding, Martin Fleissner; Thøgersen, Annett; Killi, Veronica Anne-Line Kathrine; Svenum, Ingeborg-Helene & Grandcolas, Mathieu
[Show all 10 contributors for this article]
(2023).
Operando observation of interfacial energetics at the Ta3N5/electrolyte heterojunction by ambient pressure X-ray photoelectron spectroscopy for photoelectrochemical water splitting .
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Chatzitakis, Athanasios; Zhu, Junjie; Gudmundsdottir, Jonina Björg; Strandbakke, Ragnar; Both, Kevin Gregor & Aarholt, Thomas
[Show all 12 contributors for this article]
(2022).
A monolithic and noble metal-free photoelectrochemical device of minimal engineering for efficient, unassisted water splitting.
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Kang, Xiaolan; Reinertsen, Vilde Mari; Both, Kevin Gregor; Galeckas, Augustinas; Aarholt, Thomas & Prytz, Øystein
[Show all 9 contributors for this article]
(2022).
Exsolved nanoparticles, galvanically restructured for tunable photo-electrocatalytic energy conversion.
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Kang, Xiaolan; Chaperman, Larissa; Galeckas, Augustinas; Ammar-Merah, Souad; Mammeri, Fayna & Norby, Truls
[Show all 7 contributors for this article]
(2022).
Water Vapor Photoelectrolysis in an All Solid-State Photoelectrochemical Cell
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Both, Kevin Gregor; Reinertsen, Vilde Mari; Kang, Xiaolan; Neagu, Dragos; Prytz, Øystein & Norby, Truls
[Show all 7 contributors for this article]
(2022).
Thin Film Exsolution of Metal Nanoparticles and Their Galvanic Restructuring for Plasmonically Enhanced Photocatalytic Activity.
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Both, Kevin Gregor; Reinertsen, Vilde Mari; Kang, Xiaolan; Aarholt, Thomas; Neagu, Dragos & Prytz, Øystein
[Show all 8 contributors for this article]
(2022).
Improved Photoelectrochemical Performance of SrTiO3 by Plasmonically Active Au Nanoparticles.
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Kang, Xiaolan; Reinertsen, Vilde Mari; Both, Kevin Gregor; Galeckas, Augustinas; Aarholt, Thomas & Prytz, Øystein
[Show all 9 contributors for this article]
(2022).
Galvanic Restructuring of Exsolved Nanoparticles for Plasmonic and Electrocatalytic Energy Conversion (Small 29/2022 Inside back cover feature).
Small.
ISSN 1613-6810.
18(29).
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Kang, Xiaolan; Reinertsen, Vilde Mari; Both, Kevin Gregor; Galeckas, Augustinas; Aarholt, Thomas & Prytz, Øystein
[Show all 9 contributors for this article]
(2022).
Galvanic restructuring of exsolved nanoparticles for plasmonic and electrocatalytic energy conversion
.
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Chatzitakis, Athanasios
(2021).
Her splittes vann til hydrogen og oksygen bare ved hjelp av sollys.
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Kuvshinov, Mikhail; Karazhanov, Smagul; Hallsteinsen, Ingrid & Chatzitakis, Athanasios
(2021).
Synthesis and characterization of Ni-Mo alloy for applications as cathodes in photoelectrochemical (PEC) cells.
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Chatzitakis, Athanasios
(2021).
Solar Hydrogen Production.
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Chaperman, Larissa; Mammeri, Fayna; Chatzitakis, Athanasios & Ammar, Souad
(2021).
Functionally graded, soft chemistry processed titania
photoanode for water-splitting in liquid and gas phases.
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Chatzitakis, Athanasios
(2021).
Fuel(s) from the Sun.
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Karazhanov, Smagul; Zavorotynska, Olena & Chatzitakis, Athanasios
(2021).
Organizing online international school "Materials and processes for production of solar hydrogen" within the “Complex of online and onsite lectures on materials for hydrogen generation by solar water splitting” med acronym” (COOL LONGBOAT) project.
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Karazhanov, Smagul; Zavorotynska, Olena & Chatzitakis, Athanasios
(2021).
Book of abstracts of the online international school "Materials and processes for production of solar hydrogen".
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Touni, Aikaterini; Liu, Xin; Chatzitakis, Athanasios Eleftherios; Kang, Xiaolan; Spyridou, Olga & Sotiropoulos, Sotiris
(2021).
Platinized Black Titania Nanotube HER Cathodes prepared by the Galvanic Deposition Method at CaH2-reduced Titania Nanotubes.
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Liu, Xin; Risbakk, Sanne; Almeida Carvalho, Patricia; Yang, Mingyi; Backe, Paul Hoff & Bjorås, Magnar
[Show all 8 contributors for this article]
(2020).
Hydrogenase-assisted catalysis on titania electrode oxides.
Show summary
The widespread use of fuel cells and water splitting devices for energy generation and storage is limited by the dependence on noble metal catalysts. There is thus a tremendous need for the development of efficient electrocatalysts based on Earth-abundant elements. Nature inspired hydrogenases (HydA) are metallo-enzymes that catalyze the reversible reaction of H2 to protons and electrons. Hydrogenases containing Fe at the active sites, known as [FeFe]-HydA, show activities comparable to that of Pt. This work addresses a new class of electrodes for [FeFe]-HydA attachment and bio-assisted catalysis based on TiO2 nanotubes. The conducting oxide material provides suitable electronic conduction and hydrophilicity, while the nanostructure ensures tunability (tube length, crystal orientation and pore diameter) and high surface area for HydA attachment. In this work, electron microscopy is used to characterize the bio-electrodes. Based on the experimental findings, density functional theory (DFT) calculations are used to probe the catalytic reaction sites on the HydA and address the interaction between enzymes and TiO2. The novel bioelectrode will be employed in a system of artificial photosynthesis and generation of solar fuels by simultaneous water splitting and CO2 capture and utilization.
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Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Backe, Paul Hoff; Ruan, Qiushi; Tang, Junwang & Bjørås, Magnar
[Show all 8 contributors for this article]
(2020).
The use of NMR to assess the activity of formate dehydrogenase biocatalysts for CO2 utilization.
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Chatzitakis, Athanasios
(2019).
Sol + luftfuktighet = hydrogen = ren energi.
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Chatzitakis, Athanasios Eleftherios
(2019).
Prospects of photoelectrochemical water electrolysis and the production of solar fuels.
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Liu, Xin; Chatzitakis, Athanasios Eleftherios; Almeida Carvalho, Patricia; Risbakk, Sanne; Yang, Mingyi & Backe, Paul Hoff
[Show all 7 contributors for this article]
(2019).
Enzyme-assisted Catalysis on Titania Electrodes.
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Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Norby, Truls Eivind & Bjørheim, Tor Svendsen
(2019).
Ta3N5 nanotubes loaded with Co(OH)x/Co-Pi-high photocurrent densities and improved photocorrosion resistance .
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Chatzitakis, Athanasios Eleftherios
(2019).
Artificial Photosynthesis: Mimicking nature for a sustainable energy future.
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Chatzitakis, Athanasios Eleftherios
(2019).
Can we make fuel in the future from… simply air?
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Sun, Xinwei; Chatzitakis, Athanasios Eleftherios & Norby, Truls Eivind
(2019).
Composite membranes for high temperature PEM fuel cells and electrolysers.
Show summary
Polymer electrolyte membrane(PEM) fuel cells and electrolysers offer efficient use and production of H2 for emission-free transport and sustainable energy systems. In order to reduce the cost,complexity,flooding,catalyst poisoning and degradation,operation above 80°C and at lower relative humidities(RH) is preferable. Acid doped polybenzimidazole(PBI),sulfonated polyetheretherketone(SPEEK) and their composites are being investigated for high temperature and low RH operation with sufficient conductivities. We take a critical view and a surface protonic approach to gain fundamental insight.
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Sun, Xinwei; Chatzitakis, Athanasios Eleftherios & Norby, Truls Eivind
(2019).
Polymer-ceramic composite membranes for intermediate temperature PEM fuel cells.
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Xu, Kaiqi; Grandcolas, Mathieu; Yang, Juan; Mei, Sen; Chatzitakis, Athanasios Eleftherios & Norby, Truls Eivind
(2019).
Photoelectrochemical water splitting on Ta3N5 nanotubes for H2 production
.
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Liu, Xin; Chatzitakis, Athanasios Eleftherios; Almeida Carvalho, Patricia; Backe, Paul Hoff; Yang, Mingyi & Bjørås, Magnar
[Show all 7 contributors for this article]
(2018).
Enzyme-assisted Catalysis on Black Titania Electrodes.
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Sun, Xinwei; Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios & Norby, Truls Eivind
(2018).
Can hydroxyl radicals travel far? Gas phase transport and detection after photocatalytic generation at TiO2 nanorods.
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Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Vøllestad, Einar; Ruan, Qiushi; Tang, Junwang & Norby, Truls Eivind
(2018).
Solid-state tandem photoelectrochemical cell for wet air electrolysis and hydrogen production
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Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Bjørheim, Tor Svendsen & Norby, Truls Eivind
(2018).
Surface modification of Ta3N5 nanotubes as photocatalyst for photoelectrochemical water splitting.
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Chatzitakis, Athanasios Eleftherios; Simonsen, Stian; Fontaine, Marie Laure; Thomassen, Magnus & Norby, Truls Eivind
(2018).
Conductivity of polymer-ceramic composite membranes at high T and p(H2O) using a novel PEEK sample holder.
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Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Vøllestad, Einar; Ruan, Qiushi; Tang, Junwang & Norby, Truls Eivind
(2018).
Solid-state photoelectrochemical cell for wet air electrolysis and hydrogen production.
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Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Norby, Truls Eivind; Grandcolas, Mathieu; Yang, Juan & Mei, Sen
(2018).
Ta3N5 / Co(OH)x composite as the photocatalyst for photoelectrochemical water splitting.
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Grandcolas, Mathieu; Wabende, Brian; Yang, Juan; Mei, Sen; Xu, Kaiqi & Chatzitakis, Athanasios Eleftherios
[Show all 7 contributors for this article]
(2018).
TiO2 Nanorods Decorated With Cobalt oxide as Photoanodes for a Bio-Hybrid PEC Cell.
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Fontaine, Marie-Laure; Chatzitakis, Athanasios Eleftherios; Vøllestad, Einar; Thomassen, Magnus & Norby, Truls Eivind
(2018).
Principles of proton conduction in polymer-ceramic composite membranes for PEM applications.
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Chatzitakis, Athanasios Eleftherios
(2017).
(Photo)electrochemical applications of TiO2 nanotubes
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Fleischer, Christian; Chatzitakis, Athanasios Eleftherios; Grandcolas, Mathieu; Mei, Sen & Norby, Truls Eivind
(2017).
Solid-state photoelectrochemical water splitting: Application and properties of TiO2 nanotubes.
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Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Norby, Truls Eivind; Mei, Sen; Juan, Yang & Grandcolas, Mathieu
[Show all 7 contributors for this article]
(2017).
Solid-state photoelectrochemical Cell with Tantalum Nitride Nanotubes as Photoanode.
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Yang, Juan; Mei, Sen; Grandcolas, Mathieu; Simon, Christian; Xu, Kaiqi & Chatzitakis, Athanasios Eleftherios
[Show all 10 contributors for this article]
(2017).
Synthesis of Nanosized Cobalt Oxides and Application in a Bio-hybrid Photoelectrochemical Cell for CO2 Utilization.
Show summary
CO2 capture and utilization (CCU) can alleviate the disastrous effects of greenhouse gas (GHG) emissions form the use of fossil fuels. The use of CO2 emission as feedstock for direct conversion into valuable chemicals has attracted increasing research interest worldwide. A number of approaches, such as chemical, electrochemical, photochemical and biological routes have used CO2 as a sustainable carbon resource for the production of chemicals. In the present CO2BioPEC project, a novel hybrid photoelectrochemical concept, based on solar energy and formate dehydrogenase biocatalyst is applied, as illustrated in Figure 1 (left). This multidisciplinary project aims at demonstrating a bio-hybrid photoelectrochemical cell, in which solar energy is efficiently captured and utilized to convert CO2 into energy-rich compounds, using formate dehydrogenase enzymes as biocatalysts.
Cobalt oxide is a low-cost material with a band gap that can absorb visible light. It is also a promising co-catalyst that has been widely used for oxygen evolution route. In the present work, nanosized cobalt oxide was synthesized and used as a co-catalyst on the photoanode. The results showed that the formation of cobalt oxides (Co3O4, CoOOH and Co(OH)2) is strongly dependent on the temperature and reaction time. The photochemical efficiency will be further investigated by impregnating nanosized cobalt oxides onto Ta3N4 /TaON nanotubes.
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Chatzitakis, Athanasios Eleftherios; Xu, Kaiqi & Norby, Truls Eivind
(2017).
TiO2 nanotubes as photoanode electrodes in solid-state photoelectrochemical cells.
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Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Bjørheim, Tor Svendsen & Norby, Truls Eivind
(2017).
Tantalum oxynitride for photoelectrochemical water splitting.
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Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Bjørheim, Tor Svendsen & Norby, Truls Eivind
(2017).
Fuels from the sun, sea and air-by solid-state photoelectrochemical cell.
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Fleischer, Christian; Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios & Norby, Truls Eivind
(2016).
Development of high surface area TiO2 photo-electrodes and the significance of solid-state proton conductor in water splitting photoelectrochemical cell.
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Grandcolas, Mathieu; Sahoo, Prangya Parimita; Foss, Carl Erik Lie; Xing, Wen; Polfus, Jonathan M. & Sunde, Svein
[Show all 8 contributors for this article]
(2016).
Novel photoelectrocatalytic concepts for conversion of nitrogen to fuels and chemicals.
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Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios & Norby, Truls
(2016).
An All-Solid-State Photoelectrochemical Cell for Water Splitting.
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Chatzitakis, Athanasios Eleftherios; Grandcolas, Mathieu; Xu, Kaiqi; Mei, Sen; Yang, Juan & Simon, Christian
[Show all 7 contributors for this article]
(2016).
Assessing the photoelectrocatalytic activity of C, N, F codoped TiO2 nanotubes of different lengths for oxygen evolution.
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Chatzitakis, Athanasios Eleftherios & Norby, Truls
(2015).
Solar hydrogen production.
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Chatzitakis, Athanasios Eleftherios & Norby, Truls
(2015).
Solid electrolytes for photoelectrochemical cells.
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Chatzitakis, Athanasios Eleftherios; Xu, Kaiqi; Boye, Ole; Backe, Paul Hoff; Bjorås, Magnar & Dalhus, Bjørn
[Show all 13 contributors for this article]
(2015).
Solar based H2 generation in a novel photoelectrochemical-enzymatic hybrid cell.
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Both, Kevin Gregor; Chatzitakis, Athanasios; Bergum, Kristin; Hansen, Per-Anders Stensby; Prytz, Øystein & Norby, Truls
(2023).
Plasmonically Enhanced Photocatalysis: Synthesis, Physical Properties, and Applications.
University of Oslo Livrary.
ISSN 1501-7710.
Full text in Research Archive
Show summary
In this work, plasmonic metal nanoparticles (MNPs) are utilized to improve the photoelectrochemical (PEC) response of strontium titanate (STO). These MNPs were introduced by either direct exsolution, i.e., nickel (Ni), copper (Cu), iron (Fe), ruthenium (Ru), and silver (Ag), or by galvanically replacing exsolved less noble MNPs, i.e., Ni by Gold (Au), or Cu for Ag. Au, Ag, and Cu were the materials chosen with significant plasmonic activity; Fe, Ru, Pt, and Ni were used to make MNPs with minimal plasmonic response.
Two different stoichiometries of STO were synthesized. One, La-doped A-site deficient STO (La0.6Sr0.2Ti0.9Ni0.1O3–x), was exclusively doped with Ni and utilized as powder samples. The other stoichiometry was A-site excess STO (Sr1.07Ti0.93M0.07O3±δ, where M is the dopant) was doped with various metals. These excess perovskites were studied in thin film and powder forms.
A-site excess STO thin films were deposited by pulsed laser deposition on silicon substrates. The as-deposited thin films appeared nanocrystalline or amorphous until the exsolution process was engaged. The exsolution step was studied explicitly for these A-site excess STO thin films where the formation of MNPs occurred not only at or near the thin film surface but also on grain interfaces and in bulk. Moreover, the dopant diffused significantly during the process.
While the size of the template particles depended on the exsolution conditions, the galvanic replacement reaction determined the shapes and sizes of the newly formed MNPs. The replacement time and the form (thin film/powder) of STO influenced the results, both completely replaced particles and partially replaced particles with complex structures were obtained. Additionally, more prolonged galvanic replacement reactions lead to larger particles. In turn, the specific shape of the plasmonic MNPs determined the localized surface plasmon resonance band shape and peak position.
Overall, exsolution leads to well-socketed MNPs, a property seemingly inherited by the MNPs created by galvanic replacement. Well-socketed MNPs are extremely difficult to obtain by any other technique and have a favorable localized surface plasmon resonance peak shift. The PEC response revealed that reducing STO first decreases the material’s response. Reducing it further, however, increases the PEC response significantly. Au MNPs increase the PEC performance until the MNPs reach a specific size and subsequently decrease the PEC performance when growing more prominent. This work highlights the ease by which well-socketed plasmonic MNPs can be created, some impossible to synthesize by another technique, and how different reaction conditions can change the shape and size of the MNPs, ultimately tuning the localized surface plasmon resonance band shape and peak position. The method of exsolution and galvanic replacement reaction was generalized by utilizing different elements, implying that the tuning of catalytic activity depends on the choice of elements and reaction conditions.
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Kang, Xiaolan; Norby, Truls & Chatzitakis, Athanasios
(2021).
Novel nanostructured materials for energy applications.
Universitetet i Oslo, Det matematisk-naturvitenskapelige fakultet.
ISSN 1501-7710.
2021(2465).
Show summary
Nanomaterials and nanotechnology have been flourishing greatly over the last decades and their applications are spreading almost over all the branches of science and technology. In this work, we zoomed into the synthesis and characterization of nanostructured materials. The central focus was to manipulate the compositions, morphology and structures of nanomaterials by combining various strategies like defect engineering and exsolution. Several interesting features and properties of nanostructured materials were investigated and highlighted, including the optical, plasmonic, electronic and surface properties. This process deepened our fundamental understanding of surface protonic conduction of nanocrystalline oxides and increased our control over nanostructuring of materials in order to achieve targeted functionalities. The as-prepared nanomaterials have been applied in energy- and environment-related applications, showing improved and controllable efficiency in pollutants degradation and water (vapor) splitting in photocatalytic, (photo) electrocatalytic, as well as in a solid-state photoelectrocatalytic systems.
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Xu, Kaiqi; Norby, Truls Eivind; Chatzitakis, Athanasios Eleftherios & Bjørheim, Tor Svendsen
(2020).
Artificial photosynthesis – Advanced nanomaterials and use of biocatalysts for novel photoelectrochemical cells.
Matematisk Naturvitenskapelig fakultet, Universitetet i Oslo.
ISSN 1501-7710.
2020( 2254).
Show summary
The capture and storage of solar energy in chemical form by a photoelectrochemical (PEC) cell is an elegant and simple solution to the increasing energy demands and needs for chemicals and fuels from non-fossil sources. We first developed a facile fabrication method of a monolithic solid-state PEC (SSPEC) cell, which utilizes a solid-state polymer electrolyte and minimizes the distance between the two electrodes. The recent progress in understanding of surface proton conduction in porous ceramic-based electrolytes led to the idea of using the SSPEC cell for hydrogen production through water vapor splitting. The traditionally Pt-based cathode was replaced by an earth-abundant photocathode, g-C3N4, which increased the intrinsic photo-induced electrical field by a factor of three. Such a monolithic SSPEC cell working fully in the gas phase was demonstrated first time, and can play an important role for clean energy production in rural or other areas where grid infrastructure and clean water sources are limited or absent.
CO2 utilization is considered a key player in a carbon-free energy economy, emphasising the importance of CO2 capture and conversion. We have successfully demonstrated how a bio-catalyst (enzyme) can be coupled with traditional chemical engineering for this purpose. To approach this, a stable, highly photo-active material - Ta3N5 nanotubes - has been synthesized and tested in a photoelectrochemical cell. It reaches close to its theoretical performance in photo-assisted water splitting. We then coupled the Ta3N5 nanotubes as the photoabsorber together with an optimised enzyme - formate dehydrogenase (FDH) - in a photoelectrochemical cell. The aim is to mimic natural photosynthesis to reduce CO2 into a valuable chemical form – formic acid. A solar-driven reduction of CO2 and water to formic acid at close to 100% faradaic efficiency has been reached.
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