Truls Norby

• Kanas, Nikola; Singh, Sathya Prakash; Rotan, Magnus; Desissa, Temesgen Debelo; Grande, Tor; Wiik, Kjell; Norby, Truls Eivind & Einarsrud, Mari-Ann (2019). Thermoelectric Properties of Ca3Co2−xMnxO6 (x = 0.05, 0.2, 0.5, 0.75, and 1). Materials.  ISSN 1996-1944.  12, s 497 Show summary

  High-temperature instability of the Ca3Co4−yO9+δ and CaMnO3−δ direct p-n junction causing the formation of Ca3Co2−xMnxO6 has motivated the investigation of the thermoelectric performance of this intermediate phase. Here, the thermoelectric properties comprising Seebeck coefficient, electrical conductivity, and thermal conductivity of Ca3Co2−xMnxO6 with x = 0.05, 0.2, 0.5, 0.75, and 1 are reported. Powders of the materials were synthesized by the solid-state method, followed by conventional sintering. The material Ca3CoMnO6 (x = 1) demonstrated a large positive Seebeck coefficient of 668 μV/K at 900 °C, but very low electrical conductivity. Materials with compositions with x < 1 had lower Seebeck coefficients and higher electrical conductivity, consistent with small polaron hopping with an activation energy for mobility of 44 ± 6 kJ/mol and where both the concentration and mobility of hole charge carriers were proportional to 1−x. The conductivity reached about 11 S·cm−1 at 900 °C for x = 0.05. The material Ca3Co1.8Mn0.2O6 (x = 0.2) yielded a maximum zT of 0.021 at 900 °C. While this value in itself is not high, the thermodynamic stability and self-assembly of Ca3Co2−xMnxO6 layers between Ca3Co4−yO9+δ and CaMnO3−δ open for new geometries and designs of oxide-based thermoelectric generators.

• Xing, Wen; Li, Zuoan; Peters, Thijs; Fontaine, Marie-Laure; McCann, Michael; Evans, Anna; Norby, Truls Eivind & Bredesen, Rune (2019). Improved CO2 flux by dissolution of oxide ions into the molten carbonate phase of dual-phase CO2 separation membranes. Separation and Purification Technology.  ISSN 1383-5866.  212, s 723- 727 . doi: doi.org/10.1016/j.seppur.2018.11.090
• Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Jensen, Ingvild Julie Thue; Grandcolas, Mathieu & Norby, Truls Eivind (2019). Ta3N5/Co(OH)x composites as photocatalysts for photoelectrochemical water splitting. Photochemical and Photobiological Sciences.  ISSN 1474-905X. . doi: 10.1039/C8PP00312B
• Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Vøllestad, Einar; Ruan, Qiushi; Tang, Junwang & Norby, Truls Eivind (2019). Hydrogen from wet air and sunlight in a tandem photoelectrochemical cell. International journal of hydrogen energy.  ISSN 0360-3199.  44(2), s 587- 593 . doi: https://doi.org/10.1016/j.ijhydene.2018.11.030
• Desissa, Temesgen D.; Haugsrud, Reidar; Wiik, Kjell & Norby, Truls Eivind (2018). Inter-diffusion across a direct p-n heterojunction of Li-doped NiO and Al-doped ZnO. Solid State Ionics.  ISSN 0167-2738.  320, s 215- 220 . doi: 10.1016/j.ssi.2018.03.011 Show summary

  We herein report inter-diffusion across the interface between p-type Ni0.98Li0.02O and n-type Zn0.98Al0.02O for various applications including p-n-heterojunction diodes and oxide thermoelectrics. Diffusion couples were made of polished surfaces of ceramic samples pre-sintered at 1250 and 1350 °C for Ni0.98Li0.02O and Zn0.98Al0.02O, respectively. The inter-diffusion couples were annealed at 900–1200 °C for 160 h in ambient air. Electron Probe Micro Analysis (EPMA) was used to acquire diffusion profiles, followed by fitting to Fick's second law and Whipple–Le Claire's models for bulk and grain-boundary diffusion calculation, respectively. Zn2+ diffused into Ni0.98Li0.02O mainly by bulk diffusion with an activation energy of 250 ± 10 kJ/mol, whereas Ni2+ diffused into Zn0.98Al0.02O by both bulk and enhanced grain boundary diffusion with activation energies of 320 ± 120 kJ/mol and 245 ± 50 kJ/mol, respectively. The amount of Al3+ diffused from the Al-doped ZnO into the NiO phase was too small for a corresponding diffusion coefficient to be calculated. Li-ion distribution and diffusivity were not determined due to lack of analyzer sensitivity for Li. The bulk and effective diffusivities of Zn2+ and Ni2+ into NiO and ZnO enable prediction of inter-diffusion lengths as a function of time and temperature, allowing estimates of device performance, stability, and lifetimes at different operation temperatures.

• Desissa, Temesgen D.; Kanas, Nikola; Singh, Sathya Prakash; Wiik, Kjell; Einarsrud, Mari-Ann & Norby, Truls Eivind (2018). Chemical tracer diffusion of Sr and Co in polycrystalline Ca-deficient CaMnO3-δ with CaMn2O4 precipitates. Physical Chemistry, Chemical Physics - PCCP.  ISSN 1463-9076.  20(4), s 2754- 2760 . doi: 10.1039/c7cp07471a Full text in Research Archive. Show summary

  Diffusivity on the A- and B-site of polycrystalline perovskite CaMnO3-δ with Ca deficiency and spinel CaMn2O4 (marokite) as a secondary phase was studied using chemical tracers and secondary ion mass spectrometry (SIMS) complemented by electron probe microanalysis (EPMA). Thin films containing Sr and Co chemical tracers were deposited on the polished surface of the polycrystalline composite sample followed by annealing at 800 – 1200 °C for 96 h. Diffusion profiles for each tracer were determined with SIMS, followed by calculation of diffusion coefficients by fitting to appropriate models. The Sr tracer showed mainly lattice diffusion, with an activation energy of 210±30 kJ/mol, whereas the Co tracer showed a combination of lattice and enhanced grain-boundary diffusion, with activation energies of 270±30 kJ/mol and 380±40 kJ/mol, respectively. The diffusivities may be used to predict interdiffusion and lifetime of junctions between n-type CaMnO3-δ or CaMnO3-δ/CaMn2O4 composites and metallization interlayers or p-type leg materials in oxide thermoelectrics. In particular, the relatively high effective diffusivity of Co in polycrystalline CaMnO3 δ may play a role in the reported fast formation of the secondary phase (Ca3Co2-yMnyO6) between p-type Ca3Co3.92O9+δ and n-type CaMnO3-δ in a direct p-n thermoelectric junction.

• Desissa, Temesgen D.; Schrade, Matthias & Norby, Truls Eivind (2018). Electrical Properties of a p–n Heterojunction of Li-Doped NiO and Al-Doped ZnO for Thermoelectrics. Journal of Electronic Materials.  ISSN 0361-5235.  47(9), s 5296- 5301 . doi: 10.1007/s11664-018-6394-3 Show summary

  The electrical properties of a p–n heterojunction of polycrystalline p-type Ni0.98Li0.02O and n-type Zn0.98Al0.02O have been investigated for potential applications in high-temperature oxide-based thermoelectric generators without metallic interconnects. Current–voltage characteristics of the junction were measured in a two-electrode setup in ambient air at 500–1000°C. The resistance and rectification of the junction decreased with increasing temperature. A non-ideal Shockley diode model was used to fit the measured current–voltage data in order to extract characteristic parameters of the junction, such as area specific series resistance Rs and parallel shunt resistance Rp, non-ideality factor, and the saturation current density. Rs and Rp decreased exponentially with temperature, with activation energies of 0.4 ± 0.1 eV and 1.1 ± 0.2 eV, respectively. The interface resistance of the direct p–n junction studied here is as such too high for practical applications in thermoelectrics. However, it is demonstrated that it can be reduced by an order of magnitude by using a composite of the individual materials at the interface, yielding a large effective contact area.

• Fleischer, Christian; Chatzitakis, Athanasios Eleftherios & Norby, Truls Eivind (2018). Intrinsic photoelectrocatalytic activity in oriented, photonic TiO2 nanotubes. Materials Science in Semiconductor Processing.  ISSN 1369-8001.  88, s 186- 191 . doi: 10.1016/j.mssp.2018.08.009 Show summary

  In this work, we grow oriented photonic TiO2 nanotubes (TNTs) with a well-established anodization method and their intrinsic catalytic and electronic properties are studied by means of (photo)electrochemical methods. The oriented photonic TNTs are assessed by the RctCdl (ΩF) product, which is a measure of the intrinsic photoelectrocatalytic activity (IPA) of the material. The RctCdl product decouples any surface area effects and it can be applied at any potential and accompanied reaction without knowing the actual electrochemically active surface area (EASA). Moreover, electrochemical impedance spectroscopy (EIS) is used in order to investigate the frequency dispersion in the single frequency Mott-Schottky (MS) measurement. The choice of frequency and the frequency dispersion in MS measurements in nanostructured and of high surface area semiconductors are rarely addressed and can result in erroneous values of two important parameters, i.e. flat band position and donor or acceptor densities. This work provides further insights into important electrochemical aspects and catalytic properties of high surface area nanomaterials for photoelectrochemical applications.

• Hancke, Ragnhild; Larsen, Thorbjørn V.; Xing, Wen; Li, Zuoan; Fontaine, Marie-Laure & Norby, Truls Eivind (2018). Ohmically heated ceramic asymmetric tubular membranes for gas separation. Journal of Membrane Science.  ISSN 0376-7388.  564, s 598- 604 . doi: 10.1016/j.memsci.2018.07.070
• Kanas, Nikola; Bittner, Michael; Desissa, Temesgen Debelo; Singh, Sathya Prakash; Norby, Truls Eivind; Feldhoff, Armin; Grande, Tor; Wiik, Kjell & Einarsrud, Mari-Ann (2018). All-Oxide Thermoelectric Module with in Situ Formed Non-Rectifying Complex p-p-n Junction and Transverse Thermoelectric Effect. ACS Omega.  ISSN 2470-1343.  3(8), s 9899- 9906 . doi: 10.1021/acsomega.8b01357 Full text in Research Archive. Show summary

  All-oxide thermoelectric modules for energy harvesting are attractive due to high temperature stability, low cost, and the potential to use non-scarce and non-toxic elements. Thermoelectric modules are mostly fabricated in the conventional π-design, associated with the challenge of unstable metallic interconnects at high temperature. Here, we report on a novel approach to fabrication of a thermoelectric module with an in situ formed p-p-n junction made of state-of-the-art oxides Ca3Co4-xO9+δ (p-type) and CaMnO3-CaMn2O4 composite (n-type). The module was fabricated by spark plasma co-sintering of p- and n-type powders partly separated by insulating LaAlO3. Where the n- and p-type materials originally were in contact, a layer of p-type Ca3CoMnO6 was formed in situ. The hence formed p-p-n junction exhibited ohmic behavior and a transverse thermoelectric effect, boosting the open circuit voltage of the module. The performance of the module was characterized at 700 - 900 °C, with the highest power output of 5.7 mW (around 23 mW/cm2) at 900 °C and a temperature difference of 160 K. The thermoelectric properties of the p- and n-type materials were measured in the temperature range 100 - 900 °C, where the highest zT of 0.39 and 0.05 were obtained at 700 and 800 °C, respectively, for Ca3Co4-xO9+δ and the CaMnO3-CaMn2O4 composite.

• Kanas, Nikola; Singh, Sathya Prakash; Rotan, Magnus; Saleemi, Mohsin; Bittner, Michael; Feldhoff, Armin; Norby, Truls Eivind; Wiik, Kjell; Grande, Tor & Einarsrud, Mari-Ann (2018). Influence of processing on stability, microstructure and thermoelectric properties of Ca3Co4-xO9+δ. Journal of the European Ceramic Society.  ISSN 0955-2219.  38(4), s 1592- 1599 . doi: 10.1016/j.jeurceramsoc.2017.11.011 Show summary

  Due to high figure of merit, Ca3Co4-xO9+δ (CCO) has potential as p-type material for high-temperature thermoelectrics. Here, the influence of processing including solid state sintering, spark plasma sintering and post-calcination on stability, microstructure and thermoelectric properties is reported. By a new post-calcination approach, single-phase materials were obtained from precursors to final dense ceramics in one step. The highest zT of 0.11 was recorded at 800 °C for CCO with 98 and 72 % relative densities. In situ high-temperature X-ray diffraction in air and oxygen revealed a higher stability of CCO in oxygen ( ̴ 970 °C) than in air ( ̴ 930 °C), with formation of Ca3Co2O6 which also showed high stability in oxygen, even at 1125 °C. Since achievement of phase pure high density CCO by post-calcination method in air is challenging, the phase stability of CCO in oxygen is important for understanding and further improvement of the method.

• Manabe, Ryo; Stub, Sindre Østby; Norby, Truls Eivind & Sekine, Yasushi (2018). Evaluating surface protonic transport on cerium oxide via electrochemical impedance spectroscopy measurement. Solid State Communications.  ISSN 0038-1098.  270, s 45- 49 . doi: 10.1016/j.ssc.2017.11.010
• Parras, J.P.; Genreith-Schriever, A.R.; Zhang, H.; Elm, M.T.; Norby, Truls Eivind & De Souza, R.A. (2018). Is ReO3 a mixed ionic-electronic conductor? A DFT study of defect formation and migration in a BVIO3 perovskite-type oxide. Physical Chemistry, Chemical Physics - PCCP.  ISSN 1463-9076.  20(12), s 8008- 8015 . doi: 10.1039/c7cp08214b
• Sood, Kapil; Kaswan, Jyoti; Singh, Surinder P.; Norby, Truls Eivind & Basu, Suddhasatwa (2018). Electrochemical and degradation study of Sr0.6Na0.4SiO3-δ. Journal of Solid State Electrochemistry.  ISSN 1432-8488.  22(10), s 3009- 3013 . doi: 10.1007/s10008-018-4007-y
• Stub, Sindre Østby; Thorshaug, Knut; Rørvik, Per Martin; Norby, Truls Eivind & Vøllestad, Einar (2018). The influence of acceptor and donor doping on the protonic surface conduction of TiO2. Physical Chemistry, Chemical Physics - PCCP.  ISSN 1463-9076.  20(23), s 15653- 15660 . doi: 10.1039/c8cp00571k
• Stub, Sindre Østby; Vøllestad, Einar & Norby, Truls Eivind (2018). Protonic surface conduction controlled by space charge of intersecting grain boundaries in porous ceramics. Journal of Materials Chemistry A.  ISSN 2050-7488.  6(18), s 8265- 8270 . doi: 10.1039/c7ta11088j
• Sun, Xinwei; Xu, Kaiqi; Fleischer, Christian; Liu, Xin; Grandcolas, Mathieu; Strandbakke, Ragnar; Bjørheim, Tor Svendsen; Norby, Truls Eivind & Chatzitakis, Athanasios Eleftherios (2018). Earth-Abundant Electrocatalysts in Proton Exchange Membrane Electrolyzers. Catalysts.  ISSN 2073-4344.  8(12) . doi: 10.3390/catal8120657 Full text in Research Archive. Show summary

  In order to adopt water electrolyzers as a main hydrogen production system, it is critical to develop inexpensive and earth-abundant catalysts. Currently, both half-reactions in water splitting depend heavily on noble metal catalysts. This review discusses the proton exchange membrane (PEM) water electrolysis (WE) and the progress in replacing the noble-metal catalysts with earth-abundant ones. The efforts within this field for the discovery of efficient and stable earth-abundant catalysts (EACs) have increased exponentially the last few years. The development of EACs for the oxygen evolution reaction (OER) in acidic media is particularly important, as the only stable and efficient catalysts until now are noble-metal oxides, such as IrOx and RuOx. On the hydrogen evolution reaction (HER) side, there is significant progress on EACs under acidic conditions, but there are very few reports of these EACs employed in full PEM WE cells. These two main issues are reviewed, and we conclude with prospects for innovation in EACs for the OER in acidic environments, as well as with a critical assessment of the few full PEM WE cells assembled with EACs.

• Wachowski, Sebastian Lech; Li, Zuoan; Polfus, Jonathan M. & Norby, Truls Eivind (2018). Performance and stability in H2S of SrFe0.75Mo0.25O3-δ as electrode in proton ceramic fuel cells. Journal of the European Ceramic Society.  ISSN 0955-2219.  38(1), s 163- 171 . doi: 10.1016/j.jeurceramsoc.2017.08.020
• Cerretti, G; Schrade, Matthias; Song, Xin; Balke, B; Lu, H; Weidner, T; Lieberwirth, I; Panthofer, M; Norby, Truls Eivind & Tremel, Wolfgang (2017). Thermal stability and enhanced thermoelectric properties of the tetragonal tungsten bronzes Nb8-xW9+xO47 (0 < x < 5). Journal of Materials Chemistry A.  ISSN 2050-7488.  5(20), s 9768- 9774 . doi: 10.1039/c7ta01121k
• Chatzitakis, Athanasios Eleftherios; Grandcolas, Mathieu; Xu, Kaiqi; Mei, Sen; Yang, Juan; Jensen, Ingvild Julie Thue; Simon, Christian & Norby, Truls Eivind (2017). Assessing the photoelectrochemical properties of C, N, F codoped TiO2 nanotubes of different lengths. Catalysis Today.  ISSN 0920-5861.  287, s 161- 168 . doi: 10.1016/j.cattod.2016.11.040 Full text in Research Archive. Show summary

  The aim of this work has been the photoelectrochemical (PEC) study of nanostructured photoanodes based on TiO2. Highly ordered and well adhered TiO2 nanotubes (TNTs) of different lengths (∼2–20 μm) were prepared in a two-step process in ethylene glycol solutions containing fluorides, and detailed XPS analysis showed that they have become co-doped with C, N and F. PEC measurements revealed that increasing surface area is not followed by increase in the photoconversion efficiency, but rather that an optimal balance between electroactive surface area (ESA) and charge carrier concentration exists. TNTs of around 10 μm show the optimum incident photon-to-current efficiency (IPCE) of ∼33% and an overall photoconversion efficiency of ∼6.3% under UV illumination of 4 mW cm−2 light intensity. Finally, Mott-Schottky analysis revealed significant frequency dispersion of the estimated space charge layer capacitance, which renders the accurate estimation of the flatband position and charge carrier concentration unreliable. On the other hand, more realistic charge carrier concentrations can be obtained by normalizing the capacitance per ESA.

• Elstad, Aleksander A; Nguyen, Kevin; Sartori, Sabrina & Norby, Truls Eivind (2017). On the Conductivity of KBaPO4 and Its Decomposition in Steam and Water. Journal of the Electrochemical Society.  ISSN 0013-4651.  164(7), s F885- F888 . doi: 10.1149/2.0141709jes
• Kraia, Tzouliana; Wachowski, Sebastian Lech; Vøllestad, Einar; Strandbakke, Ragnar; Konsolakis, M.; Norby, Truls Eivind & Marnellos, G.E. (2017). Electrochemical performance of Co3O4/CeO2 electrodes in H2S/H2O atmospheres in a proton-conducting ceramic symmetrical cell with BaZr0.7Ce0.2Y0.1O3 solid electrolyte. Solid State Ionics.  ISSN 0167-2738.  306, s 31- 37 . doi: 10.1016/j.ssi.2017.04.010 Full text in Research Archive.
• Malerød-Fjeld, Harald; Clark, Daniel Ryan; Yuste-Tirados, Irene; Zanón, Raquel; Catalán-Martinez, David; Beeaff, Dustin; Morejudo, Selene Hernandez; Vestre, Per K.; Norby, Truls Eivind; Haugsrud, Reidar; Serra, José M. & Kjølseth, Christian (2017). Thermo-electrochemical production of compressed hydrogen from methane with near-zero energy loss. Nature Energy.  ISSN 2058-7546.  2(12), s 923- 931 . doi: 10.1038/s41560-017-0029-4
• Robinson, Shay Alexander; Kjølseth, Christian & Norby, Truls Eivind (2017). Comparison of Cu and Pt point-contact electrodes on proton conducting BaZr0.7Ce0.2Y0.1O3−δ. Solid State Ionics.  ISSN 0167-2738.  306, s 38- 47 . doi: 10.1016/j.ssi.2017.02.014
• Stefan, Elena; Stange, Marit Synnøve Sæverud; Denonville, Christelle; Larring, Yngve; Hildenbrand, Nicolas; Norby, Truls Eivind & Haugsrud, Reidar (2017). Layered microstructures based on BaZr0.85Y0.15O3−δ by pulsed laser deposition for metal-supported proton ceramic electrolyser cells. Journal of Materials Science.  ISSN 0022-2461.  52(11), s 6486- 6497 . doi: 10.1007/s10853-017-0884-1 Full text in Research Archive.
• Strandbakke, Ragnar; Vøllestad, Einar; Robinson, Shay Alexander; Fontaine, Marie-Laure & Norby, Truls Eivind (2017). Ba0.5Gd0.8La0.7Co2O6-δ infiltrated in porous BaZr0.7Ce0.2Y0.1O3 backbones as electrode material for proton ceramic electrolytes. Journal of the Electrochemical Society.  ISSN 0013-4651.  164(4), s F196- F202 . doi: 10.1149/2.0141704jes
• Stub, Sindre Østby; Vøllestad, Einar & Norby, Truls Eivind (2017). Mechanisms of Protonic Surface Transport in Porous Oxides: Example of YSZ. Journal of Physical Chemistry C.  ISSN 1932-7447.  121(23), s 12817- 12825 . doi: 10.1021/acs.jpcc.7b03005 Full text in Research Archive.
• Vøllestad, Einar; Schrade, Matthias; Segalini, Julie; Strandbakke, Ragnar & Norby, Truls Eivind (2017). Relating defect chemistry and electronic transport in the double perovskite Ba1-xGd0.8La0.2+xCo2O6-d (BGLC). Journal of Materials Chemistry A.  ISSN 2050-7488.  5(30), s 15743- 15751 . doi: 10.1039/c7ta02659e
• Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios & Norby, Truls (2017). Solid-state photoelectrochemical cell with TiO2 nanotubes for water splitting. Photochemical and Photobiological Sciences.  ISSN 1474-905X.  16(1), s 10- 16 . doi: 10.1039/c6pp00217j Full text in Research Archive.

View all works in Cristin

• Norby, Truls Eivind (2019). Novel aspects of electrocatalysis for hydrogen.
• Balaguer, Maria; Tarach, Mateusz; Strandbakke, Ragnar; Bjørheim, Tor Svendsen; Mielewczyk-Gryn, Aleksandra; Wachowski, Sebastian; Lewandowska, Iga; Sørby, Magnus Helgerud; Gazda, Maria; Norby, Truls Eivind & Serra, José Manuel (2018). Hydration Stability of Mixed Conducting Layered Oxides.
• Bondevik, Tarjei; Norby, Truls Eivind & Bjørheim, Tor Svendsen (2018). Validating approximations commonly used in space charge modelling.
• 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.
• Clark, Daniel Ryan; Malerød-Fjeld, Harald; Budd, Michael; Catalán-Martinez, David; Beeaff, Dustin; Norby, Truls Eivind & Haugsrud, Reidar (2018). Design and development of next-generation protonic reactors.
• Dayaghi, Amir Masoud; Stange, Marit Synnøve Sæverud; Denonville, Christelle; Larring, Yngve; Rørvik, Per Martin & Norby, Truls Eivind (2018). Key challenges in fabrication of metal-supported proton conducting electrolyser cells.
• Desissa, Temesgen D.; Norby, Truls Eivind & Haugsrud, Reidar (2018). Stability and properties of materials and interfaces for oxide thermoelectrics. Series of dissertations submitted to the Faculty of Mathematics and Natural Sciences, University of Oslo.. 1969.
• Fleischer, Christian; Bjørheim, Tor Svendsen & Norby, Truls Eivind (2018). Point Defects in Transition Metal Dichalcogenides. Show summary

  Defect chemistry has given the possibility to control and tune properties to obtain better functional bulk materials. In comparison, and despite the recent interest and prospects of twodimensional materials, their defect chemistry remains mainly unexplored. We believe that an understanding of the influence of the dielectric environment on the defect chemistry and properties is crucial for further developing new and superior 2D materials. Here, we present results from our computational work on selected point defects in monolayer MoS2. Investigated defects comprises molybdenum and sulphur vacancies in addition to hydrosulfide on sulphur site.

• Fleischer, Christian; Bjørheim, Tor Svendsen; Polfus, Jonathan M. & Norby, Truls Eivind (2018). Point Defects in Monolayer MoS2.
• Fleischer, Christian; Polfus, Jonathan M.; Bjørheim, Tor Svendsen & Norby, Truls Eivind (2018). Defect Chemistry of Few- and Monolayer MoS2. Show summary

  Defect chemistry has given the possibility to control and tune properties to obtain better functional bulk materials. In comparison, and despite the recent interest and prospects of two-dimensional materials, their defect chemistry remains mainly unexplored. We believe that an understanding of the influence of the dielectric environment on the defect chemistry and properties is crucial for further developing new and superior 2D materials. Here, we present results for molybdenum disulphide (MoS2) films on Si/SiO2 substrates. Methods comprise magnetron sputtering of Mo with subsequent annealing in H2S atmosphere and the chemical vapour transport method. The films and defects are characterised by AFM, XPS, photoluminescence, optical microscopy and Raman spectroscopy in addition to electrical measurements in controlled atmospheres. Ab initio computations on a variety of point defects and defect clusters further elucidate the defect chemistry.

• 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.
• Grandcolas, Mathieu; Wabende, Brian; Yang, Juan; Mei, Sen; Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios & Norby, Truls Eivind (2018). TiO2 Nanorods Decorated With Cobalt oxide as Photoanodes for a Bio-Hybrid PEC Cell.
• Hu, Yang & Norby, Truls Eivind (2018). La-SrTiO3 point-contact electrode on proton conducting BaZr0.85Y0.15O3-δ.
• Lukaszuk, Katarzyna Anna; Carretero, Isabel Díaz; Louis, Benoit & Norby, Truls Eivind (2018). Controlling the morphology of zeolite crystals in OFF and MTT/TON systems. Series of dissertations submitted to the Faculty of Mathematics and Natural Sciences, University of Oslo.. 2038.
• Ma, Quanbao; Ibishi, Diamanta & Norby, Truls Eivind (2018). Preparation and characterization of Ru/CeO2 catalysts for electrically enhanced ammonia synthesis.
• Norby, Truls Eivind (2018). Dekarbonisering - henger Norge med?.
• Norby, Truls Eivind (2018). Electrodics for proton ceramic electrochemical cells.
• Norby, Truls Eivind (2018). Hydrogen (prisforedrag for Guldberg-Waage-medaljen 2018). Show summary

  Starting my first research in inorganic chemistry, I stumbled across hydrogen where and when I and everyone else did not expect to find it – it is so common and yet so un-common. It makes bonds more different than any other element – polar and purely covalent as protons and atoms, metallic when it pleases, and ionic as hydride ions. Consequently, it shows up in very different forms and locations and has taken me for a journey to my roots in physical chemistry and to electrochemistry – some things discovered and some mysteries remaining. Hydrogen holds a historical role in the establishment of major Norwegian industry, and we today host world-leading production of electrolyzers for the emerging markets of hydrogen for storage and as carrier of renewable electrical energy. Many different types of solids contain or may take up water and become solid-state proton conductors by various mechanisms of transport. They may be used as electrolytes in novel types of fuel cells and electrolyzers for hydrogen and renewable energy, as well as in electrocatalytic reactors for upgrading natural gas to liquids or hydrogen with minimal carbon emissions or with carbon capture and storage. The research involves experimental and ab initio computational methods to understand hydrogen in its various forms from gas phase, via surfaces and charge transfer at electrode interfaces, into mobile ions in crystalline or liquid-like condensed phases.

• Norby, Truls Eivind (2018). Proton ceramic cells for fuel cells, electrolyzers, and natural gas conversion.
• Norby, Truls Eivind (2018). Proton ceramics.
• Norby, Truls Eivind (2018). The chemistries of proton ceramic electrochemical cells.
• Norby, Truls Eivind; Min, Chen & Bondevik, Tarjei (2018). Space-charge and its effects on solid-oxide electrode kinetics.
• Norby, Truls Eivind; Min, Chen; Bondevik, Tarjei & Polfus, Jonathan M. (2018). Space Charge Layers and Their Role for Properties of Interfaces in Solid State Ionics.
• Stange, Marit Synnøve Sæverud; Dayaghi, Amir Masoud; Denonville, Christelle; Rørvik, Per Martin; Larring, Yngve & Norby, Truls Eivind (2018). Fabrication of Metal Supported Protonic Ceramic Electrolyser Cells (PCEC).
• Strandbakke, Ragnar; Bjørheim, Tor Svendsen; Mielewczyk-Gryn, Aleksandra; Wachowski, Sebastian; Lewandowska, Iga; Balaguer, Maria; Sørby, Magnus Helgerud; Gazda, Maria; Serra, José Manuel & Norby, Truls Eivind (2018). Governing Principles in Hydration of Mixed Conducting Oxides.
• Strandbakke, Ragnar; Gunnæs, Anette Eleonora; Carvalho, Patricia A.; Mielewczyk-Gryn, Aleksandra; Wachowski, Sebastian; Balaguer, Maria; Sørby, Magnus Helgerud & Norby, Truls Eivind (2018). Coupled hydration, cation reorganization and red-ox in MIEC perovskites.
• Strandbakke, Ragnar; Wragg, David; Carvalho, Patricia; Mielewczyk-Gryn, Aleksandra; Wachowski, Sebastian; Balaguer, Maria; Sørby, Magnus Helgerud & Norby, Truls Eivind (2018). Coupled hydration and red-ox in MIEC BGLC perovskites.
• 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.
• Wachowski, Sebastian; Levandowska, Iga; Sørby, Magnus Helgerud; Balaguer, Maria; Bjørheim, Tor Svendsen; Gazda, Maria; Serra, José Manuel; Strandbakke, Ragnar; Norby, Truls Eivind & Mielewczyk-Gryn, Aleksandra (2018). Governing Principles in Hydration of Mixed Conducting Oxides: Structure and Hydration of BaLnCo2O6-d.
• Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Bjørheim, Tor Svendsen & Norby, Truls Eivind (2018). Surface modification of Ta3N5 nanotubes as photocatalyst for photoelectrochemical water splitting.
• 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.
• 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.
• 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.
• Chatzitakis, Athanasios Eleftherios; Xu, Kaiqi & Norby, Truls Eivind (2017). TiO2 nanotubes as photoanode electrodes in solid-state photoelectrochemical cells.
• Chen, Min; Lozano, Helena Téllez; Druce, John; Matsumoto, Hiroshige; Sazinas, Rokas; Polfus, Jonathan M. & Norby, Truls Eivind (2017). Surface chemistry of BaZr0.9Y0.1O3-δ and its effect on the electrochemical properties of a Ni/BaZr0.9Y0.1O3-δ interface for proton ceramic electrochemical cells.
• Desissa, Temesgen D. & Norby, Truls Eivind (2017). Electrical properties and diffusion coefficient analysis of NiO:Li/ZnO:Al p-n heterojunction for oxide based thermoelectric generators.
• Fleischer, Christian; Chatzitakis, Athanasios Eleftherios; Grandcolas, Mathieu; Mei, Sen & Norby, Truls Eivind (2017). Solid-state photoelectrochemical water splitting: Application and properties of TiO2 nanotubes..
• Hancke, Ragnhild; Norby, Truls Eivind; Fontaine, Marie-Laure; Mtabazi, Sahini & Xing, Wen (2017). Self-healing ceramic membranes with increased lifetime for CO2 capture in industrial processes and power production.
• Jeu Chiem, Kevin; Prytz, Øystein & Norby, Truls Eivind (2017). Nanoscale measurements of oxidation states in the CaMnO3/LaMnO3 system using Electron Energy Loss Spectroscopy..
• Kanas, Nikola; Bittner, Michael; Singh, Sathya Prakash; Desissa, Temesgen D.; Feldhoff, Armin; Norby, Truls Eivind; Grande, Tor; Wiik, Kjell & Einarsrud, Mari-Ann (2017). Development of all-oxide thermoelectric device.
• Løken, Andreas; Haugsrud, Reidar; Norby, Truls Eivind & Bjørheim, Tor Svendsen (2017). Hydration thermodynamics of oxides.
• Norby, Truls Eivind (2017). Advances in Proton Ceramic Fuel Cells, Steam Electrolyzers, and Dehydrogenation Reactors Based on Materials and Process Optimizations.
• Norby, Truls Eivind (2017). Grønn Gjødselproduksjon i 2050. Noe nytt under solen?.
• Norby, Truls Eivind (2017). High temperature electrolysis using proton conducting ceramic electrolytes.
• Norby, Truls Eivind (2017). Hydrogen.
• Norby, Truls Eivind (2017). Novel approaches for conversion of H2O, CO2, and N2 with renewables.
• Norby, Truls Eivind (2017). Principles and applications of coexistent p-n junctions.
• Norby, Truls Eivind (2017). Teknologi kan redusere klimagassutslipp i landbruket.
• Norby, Truls Eivind; Hancke, Ragnhild; Fontaine, Marie-Laure & Grande, Tor (2017). Self-Healing and Self-Assembling Ceramic Electrolytes and Membranes.
• Robinson, Shay Alexander; Norby, Truls Eivind; Kjølseth, Christian & Coors, W. Grover (2017). Development of Cu-Based Electrodes for Proton-Conducting Membrane Reactors. Series of dissertations submitted to the Faculty of Mathematics and Natural Sciences, University of Oslo.. 1906.
• Singh, Sathya Prakash; Kanas, Nikola; Norby, Truls Eivind; Johnsson, Mats; Einarsrud, Mari-Ann & Wiik, Kjell (2017). Thermoelectric properties of (La0.12Sr0.88)0.95TiO3 between 100 and 900 oC at reducing conditions.
• Stange, Marit Synnøve Sæverud; Denonville, Christelle; Larring, Yngve; Stefan, Elena; Rørvik, Per Martin; Haugsrud, Reidar & Norby, Truls Eivind (2017). Manufacturing of Metal Supported Protonic Ceramic Electrolyser Cells (PCEC).
• Strandbakke, Ragnar; Vøllestad, Einar & Norby, Truls Eivind (2017). Development of oxygen-side electrodes for proton conducting fuel cells and electrolysers.
• Strandbakke, Ragnar; Vøllestad, Einar; Norby, Truls Eivind; Sartori, Sabrina; Guzik, Matylda Natalia & Lang, Julien (2017). Hydration and structural properties of mixed conductor Ba1‑xGd0.8La0.2+xCo2O6-δ (BGLC).
• Strandbakke, Ragnar; Vøllestad, Einar; Norby, Truls Eivind; Sartori, Sabrina; Guzik, Matylda Natalia & Lang, Julien (2017). Hydration and structural properties of mixed conductor Ba1‑xGd0.8La0.2+xCo2O6-δ (BGLC).
• Stub, Sindre Østby; Haugsrud, Reidar & Norby, Truls Eivind (2017). Protonic Conduction in Porous Oxides.
• Stub, Sindre Østby; Vøllestad, Einar; Rørvik, Per Martin & Norby, Truls Eivind (2017). On the role of grain boundaries in surface protonics.
• Stub, Sindre Østby; Vøllestad, Einar; Rørvik, Per Martin & Norby, Truls Eivind (2017). Protonic conduction in porous oxides.
• Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Bjørheim, Tor Svendsen & Norby, Truls Eivind (2017). Fuels from the sun, sea and air-by solid-state photoelectrochemical cell.
• Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Bjørheim, Tor Svendsen & Norby, Truls Eivind (2017). Tantalum oxynitride for photoelectrochemical water splitting.
• Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Norby, Truls Eivind; Mei, Sen; Juan, Yang; Grandcolas, Mathieu & Simen, Christian (2017). Solid-state photoelectrochemical Cell with Tantalum Nitride Nanotubes as Photoanode.
• Yang, Juan; Mei, Sen; Grandcolas, Mathieu; Simon, Christian; Xu, Kaiqi; Chatzitakis, Athanasios Eleftherios; Norby, Truls Eivind; Yang, Mingyi; Backe, Paul Hoff & Bjørås, Magnar (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.

• Chatzitakis, Athanasios Eleftherios; Grandcolas, Mathieu; Xu, Kaiqi; Mei, Sen; Yang, Juan; Simon, Christian & Norby, Truls (2016). Assessing the photoelectrocatalytic activity of C, N, F codoped TiO2 nanotubes of different lengths for oxygen evolution.
• Chen, Min & Norby, Truls (2016). Space Charge Layer Effect at the Ni/BaZr0.9Y0.1O3-δ Electrode Interface in Proton Ceramic electrochemical Cells.
• Chen, Min & Norby, Truls (2016). Surface chemistry of BaZr0.9Y0.1O3-δ and its effect on the electrochemical properties of a Ni/BaZr0.9Y0.1O3-δ interface.
• Desissa, Temesgen D. & Norby, Truls (2016). A p-Ni1-xLixO and n-Zn1-xAlxO p-n junctions for oxide-based thermoelectric modules. Show summary

  A p-type Ni0.98Li0.02O and n-type Zn0.98Al0.02O thermoelectric materials have been synthesized from their respective powder precursors via solid state synthesis technique from which a pellets were obtained by uniaxial pressing. The pellets were sintered at a sintering temperature of 1523 K and 1623 K for Ni0.98Li0.02O and Zn0.98Al0.02O, respectively. The sintered samples were carefully polished to a surface finish of ¼ μm by using a diamond abrasive before establishing a p-n junction. After a p-n junction is formed, an I-V and C-V measurement has been performed. The p-n junction is rectifying in the lower temperature region and became ohmic in the highest temperature. A p-n junction resistivity was delineated from the overall resistivity and it constituted the main part of the overall resistivity. A built-in voltage of 0.875± 0.039 V was obtained from a C-V measurement at a frequency of 1 MHz at a temperature of 1173 K. Additionally, the p-n junction was annealed in ambient air at 1173 K for 160 hours to determine inter-diffusion coefficient using an electron probe micro analyzer (EPMA). The bulk diffusion coefficient of Ni2+ and Zn2+ was about 4.08*10-15 cm2/s and 4.51 * 10-15 cm2/s, respectively, after fitting to the solution of Fick’s second law of diffusion equation with a semi-infinite source type.

• 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..
• Fontaine, Marie-Laure; Denonville, Christelle; Strandbakke, Ragnar; Serra, José Manuel; Beeaff, Dustin R.; Vigen, Camilla Kaori; Vøllestad, Einar & Norby, Truls (2016). Development of Tubular Proton Ceramic Electrolysers (PCEs).
• Fontaine, Marie-Laure; Denonville, Christelle; Strandbakke, Ragnar; Vøllestad, Einar; Norby, Truls; Bredesen, Rune; Vigen, Camilla Kaori & Beeaff, Dustin R. (2016). Proton conducting electrolytes integrated in tubular segmented-in-series cells for pressurized hydrogen production.
• Fontaine, Marie-Laure; Vøllestad, Einar; Polfus, Jonathan M.; Denonville, Christelle; Xing, Wen; Li, Zuoan; Norby, Truls & Bredesen, Rune (2016). Proton Conducting Electrolysers with Tubular Segmented-in-series Cells for Hydrogen Production.
• Fontaine, Marie-Laure; Xing, Wen; Bredesen, Rune; Denonville, Christelle; Polfus, Jonathan M.; Strandbakke, Ragnar; Vøllestad, Einar; Norby, Truls; Beeaff, Dustin R. & Vigen, Camilla Kaori (2016). Proton conducting electrolysers with tubular segmented-in-series cells for hydrogen production.

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