Search results for "O2"
showing 10 items of 1115 documents
2D slab models of TiO2 nanotubes for simulation of water adsorption: Validation over a diameter range
2020
Financial support provided by Scientific Research Project for Students and Young Researchers Nr. SJZ/2019/2 realized at the Institute of Solid State Physics, University of Latvia is greatly acknowledged. Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under Grant Agreement No. 739508, project CAMART 2 .
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
2021
Financial support provided by Scientific Research Project for Students and Young Researchers, Latvia Nr. SJZ/2018/7 realized at the Institute of Solid State Physics, University of Latvia is greatly acknowledged. Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART2.
Synthesis and high-throughput testing of multilayered supported ionic liquid catalysts for the conversion of CO2 and epoxides into cyclic carbonates
2014
Multilayered covalently supported ionic liquid phase (mlc-SILP) materials were synthesised by grafting different bis-vinylimidazolium salts on thiol-functionalised silica. These materials, which contain a cross-linked oligomeric network of imidazolium units, were characterised and tested as catalysts for the reaction of carbon dioxide with various epoxides to produce cyclic carbonates. The materials prepared by supporting a bis-imidazolium iodide salt with xylene or octane as a linker between the imidazolium units were identified as the most active catalysts and displayed high turnover numbers and improved productivity compared to known supported ionic liquid catalysts. The most promising m…
ZrO2 based materials: preparation, characterization and photocatalytic activity for 2-propanol oxidation and CO2 reduction
2017
ZrO2 based materials: preparation, characterization and photocatalytic activity for 2-propanol oxidation and CO2 reduction
Amine functionalized ZrO2 nanoparticles as biocompatible and luminescent probes for ligand specific cellular imaging
2015
Surface functionalized ZrO2 nanoparticles show strong photoluminescence and are a versatile tool for cellular targeting due to their chemical functionality. They are highly photostable, biocompatible and amenable to coupling with bioligands (e.g. secondary goat anti-rabbit antibody (GAR) and tri-phenyl phosphine (TPP)) via carbodiimide chemistry. Antibody (GAR) functionalized ZrO2 nanoparticles were used to image the nuclear protein Sirt6, whereas triphenyl phosphonium ion (TPP) functionalized ZrO2 nanoparticles specifically targeted the mitochondria. The versatility and easiness of the ZrO2 surface modification opens up new possibilities for designing non-toxic water dispersible and photos…
Short term adaptive response of symbiotic N2 fixation in pea to root pruning of half the root system, linked to the availability of carbon assimilates
2014
Symbiotic N fixation of legumes is very sensitive to environmental stresses, like pea pests damaging nodulated roots. However, the impact on their N uptake capacity and plant growth has not been studied so far.We analyzed the adaptive response symbiotic N2 fixation and plant growth of pea wild type Frisson and hypernodulating mutants P64, P118 and P121 mutated respectively on genes SYM28, SYM29 and NOD3 to root pruning of half the root system at the end of the vegetative stage. The adaptive responses of pea: cv. Frisson and 3 of its hypernodulating mutants were compared under varying carbon supplies from photosynthesis.At 380 ppm, mutant P118 showed the lowest decrease of the specific activ…
Syntheses of TiO2 anatase nanocrystals with controlled size distribution. Influence of the crystallites size on the Raman spectrum and investigation …
2006
The determination of the size and the size distribution of anatase TiO2 nanopowders using Raman spectroscopy is presented. Several synthesis methods (soft chemistry, water-in-oil microemulsion, continuous hydrothermal synthesis) are used in order to control the size (from 3 to 20 nm), shape, phase and size distribution. The shift and width of the anatase Eg peak are often used to obtain the nanoparticles size. Homever, this peak is also sensitive to nonstoichiometry and others parameters. Low-frequency Raman scattering does not suffer from this problem. Size distibutions obtained by Raman spectroscopy and MET micrographs are compared. Finally, in situ Raman spectroscopy is used to study the…
Initial stages of metal oxides thin films growth by MOCVD: physicochemical characterisation of the film/substrate interface
2006
The initial stages of Metalorganic Chemical Vapour Deposition (MOCVD) of TiO2 thin films on Si(100) were studied in situ by surface analyses (XPS, ARXPS, AES). An original experimental set-up was built for this purpose and developed. Information obtained from these in situ experiments was completed by ex situ characterisations (HRTEM, SIMS, GIXRD...).The formation of an interfacial SiOy<2 layer resulting of the interaction of the precursor Ti(OCH(CH3)2)4 with the substrate takes place before the formation of stoichiometric TiO2 and leads to the presence of carbon at the interface. At the deposition temperature, 675 °C, silicon diffusion within the TiO2 external layer was also revealed. Conc…
Study of TiO2 nanostructures grown in a MOCVD reactor in presence of metallic catalysts. Valorization of these TiO2 nanostructures
2017
Within the Nanoform Theme, Ax Nanosciences, ICB, we realize the growth of 1D, 2D and 3D hybrid nanostructures based on TiO2 by MOCVD. Our work deals with the theoretical aspect of the formation of these nanostructures (growth and kinetic models, structure and texture) and the study of photoelectric, optical and physicochemical properties as well as the development of applications of these structures in physics (random laser), photocatalysis, energy (solar cells). Under certain perfectly controlled conditions, we obtain original TiO2 structures not yet described in the literature: membranes, rods , canals, crucibles, COHN (COaxiales Heterostructures Nanowires). Our previous work made it poss…
ZnO(core)/TiO2(shell) composites : influence of TiO2 microstructure, N-doping and decoration with Au nanoparticles on photocatalytic and photoelectro…
2017
The aim of the thesis is to study the influence of microstructure of ZnO/TiO2 composites on their properties in photocatalytic degradation of organic pollutants, and in photoassisted water oxidation. To realize such study we chose the design based on ZnO nanorods supported on ITO (Indium Tin Oxide)-coated glass electrode. The ZnO nanorods were then covered with a layer of TiO2 under different conditions. The composition and microstructure of the obtained ZnO(core)/TiO2(shell) composites were modified in the aim to elucidate how these parameters influence their photocatalytic activity. The results of studies lead to elaboration of two most distinctive variants of sol-gel procedure that allow…