Xin Liu

• Grini, Sigbjørn; Sopiha, Kostiantyn; Ross, Nils; Liu, Xin; Bjørheim, Tor Svendsen; Platzer-Björkman, Charlotte; Persson, Clas & Vines, Lasse (2019). Strong Interplay between Sodium and Oxygen in Kesterite Absorbers: Complex Formation, Incorporation, and Tailoring Depth Distributions. Advanced Energy Materials.  ISSN 1614-6832.  9(27), s 1- 9 . doi: 10.1002/aenm.201900740 Full text in Research Archive.
• Liu, Xin; Almeida Carvalho, Patricia; Getz, Marit Norderhaug; Norby, Truls Eivind & Chatzitakis, Athanasios Eleftherios (2019). Black Anatase TiO2 Nanotubes with Tunable Orientation for High Performance Supercapacitors. Journal of Physical Chemistry C.  ISSN 1932-7447.  126(36), s 21391- 21940 . doi: 10.1021/acs.jpcc.9b05070 Show summary

  Black TiO2 is a versatile material that finds many applications in the field of photocatalysis but also in energy storage devices, such as supercapacitors. In this work, a new method is developed for the synthesis of black TiO2 in the form of nanotubes. Amorphous TiO2 nanotubes (TNTs) are annealed and reduced in the presence of CaH2, and by a simple manipulation, we are able to obtain control over the preferred crystal orientation. The reduced TNTs show high power and energy densities, as well as unprecedented stability under intensive charge/discharge cycling. The oriented reduced TNTs show metallic-like behavior with improved conductivity when compared to the polycrystalline analogue. This work contributes to the development of highly robust and efficient oxides for electrode material in supercapacitors.

• Liu, Xin; Bjørheim, Tor Svendsen; Vines, Lasse; Fjellvåg, Øystein; Granerød, Cecilie Skjold; Prytz, Øystein; Yamamoto, Takafumi; Kageyama, Hiroshi; Norby, Truls Eivind & Haugsrud, Reidar (2019). Highly Correlated Hydride Ion Tracer Diffusion in SrTiO3–xHx Oxyhydrides. Journal of the American Chemical Society.  ISSN 0002-7863.  141(11), s 4653- 4659 . doi: 10.1021/jacs.8b12985 Full text in Research Archive.
• Liu, Xin; Bjørheim, Tor Svendsen & Haugsrud, Reidar (2018). Formation of defects and their effects on hydride ion transport properties in a series of K2NiF4-type oxyhydrides. Journal of Materials Chemistry A.  ISSN 2050-7488.  6(4), s 1454- 1461 . doi: 10.1039/c7ta08435h
• Liu, Xin; Zhang, Jie; Huang, Chongpin & Sun, Xiuliang (2018). Density Functional Theory Study of Cu-ZSM-5-Catalyzed C-H Bond Activation: The Importance of Active Centers. Journal of Physical Chemistry C.  ISSN 1932-7447.  122(50), s 28645- 28651 . doi: 10.1021/acs.jpcc.8b08137
• 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.  8:657(12), s 1- 41 . 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.

• Liu, Xin; Bjørheim, Tor Svendsen & Haugsrud, Reidar (2017). Formation and migration of hydride ions in BaTiO3-xHx oxyhydride. Journal of Materials Chemistry A.  ISSN 2050-7488.  5(3), s 1050- 1056 . doi: 10.1039/c6ta06611a
• Liu, Xin; Bjørheim, Tor Svendsen & Haugsrud, Reidar (2016). Thermochemical properties of rare-earth oxyhydrides from first principles phonon calculations. RSC Advances.  ISSN 2046-2069.  6(12), s 9822- 9826 . doi: 10.1039/c5ra26552e
• Løken, Andreas; Saeed, Sarmad Waheed; Norderhaug, Marit; Liu, Xin & Bjørheim, Tor Svendsen (2016). Alkali metals as efficient A-site acceptor dopants in proton conducting BaZrO3. Journal of Materials Chemistry A.  ISSN 2050-7488.  4(23), s 9229- 9235 . doi: 10.1039/c6ta01446a Full text in Research Archive.

View all works in Cristin

• Liu, Xin; Risbakk, Sanne; Almeida Carvalho, Patricia; Yang, Mingyi; Backe, Paul Hoff; Bjorås, Magnar; Norby, Truls Eivind & Chatzitakis, Athanasios Eleftherios (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.

• Li, Zuoan; Liu, Xin & Haugsrud, Reidar (2019). Dissociation of oxygen on oxides determined by a modified gas phase analysis (GPA).
• Liu, Xin; Chatzitakis, Athanasios Eleftherios; Almeida Carvalho, Patricia; Risbakk, Sanne; Yang, Mingyi; Backe, Paul Hoff & Norby, Truls Eivind (2019). Enzyme-assisted Catalysis on Titania Electrodes.
• Norby, Truls Eivind; Liu, Xin; Bjørheim, Tor Svendsen & Haugsrud, Reidar (2019). Hydride ion conduction.
• Thoréton, Vincent; Bjørheim, Tor Svendsen; Liu, Xin; Li, Zuoan & Haugsrud, Reidar (2019). Influence of water vapour on the surface exchange kinetics of functional oxides.
• Grini, Sigbjørn; Ross, Nils; Liu, Xin; Platzer-Björkman, Charlotte; Persson, Clas & Vines, Lasse (2018). How is oxygen introduced in Cu2ZnSnS4 solar cell processing?.
• Grini, Sigbjørn; Ross, Nils; Sopiha, Kostiantyn; Liu, Xin; Persson, Clas; Platzer-Björkman, Charlotte & Vines, Lasse (2018). Introduction of oxygen into kesterite processing.
• Liu, Xin; Haugsrud, Reidar; Bjørheim, Tor Svendsen & Fjellvåg, Helmer (2018). Defect, Stability and Transport in Oxyhydrides. Series of dissertations submitted to the Faculty of Mathematics and Natural Sciences, University of Oslo.. 1980.
• Liu, Xin; Bjørheim, Tor Svendsen & Haugsrud, Reidar (2016). Hydride migration and electron localization in BaTiO3-xHx oxyhydride.
• Løken, Andreas; Saeed, Sarmad Waheed; Norderhaug, Marit; Liu, Xin & Bjørheim, Tor Svendsen (2016). Alkali metals as efficient A-site acceptor dopants in proton conducting BaZrO3.
• Fjellvåg, Øystein Slagtern; Fjellvåg, Helmer; Liu, Xin; Haugsrud, Reidar & Sjåstad, Anja Olafsen (2015). Hydride oxides with perovskite related structure: Case study of La2LiHO3.

View all works in Cristin