Search results for "O2"

Structural Modification Processes in Bulk and Nano-sized Amorphous SiO2 Systems.

2011

Colorimetric gas detection by the varying thickness of a thin film of ultrasmall PTSA-coated TiO

2016

Colorimetric gas sensing is demonstrated by thin films based on ultrasmall TiO2 nanoparticles (NPs) on Si substrates. The NPs are bound into the film by p-toluenesulfonic acid (PTSA) and the film is made to absorb volatile organic compounds (VOCs). Since the color of the sensing element depends on the interference of reflected light from the surface of the film and from the film/silicon substrate interface, colorimetric detection is possible by the varying thickness of the NP-based film. Indeed, VOC absorption causes significant swelling of the film. Thus, the optical path length is increased, interference wavelengths are shifted and the refractive index of the film is decreased. This cause…

Photocatalytic Properties of Nanostructured TiO2 Powders Obtained by Thermohydrolysis of TiOSO4

2012

Fabrication of Nanostructured Ni and Ni-IrO2 electrodes for wateralkaline electrolyzer

2016

In the field of water-alkaline electrolyzer, the develop of nanoporous nickel electrodes with low cost and high electrocatalysis efficiency is one of the potential approaches to increase their performance [1]. To obtain nanostructured electrodes, a facile approach is that of template electrosynthesis. With this method we have obtained electrodes made of nanowires of Ni that have a very high surface area. These electrode were obtained by a two-step procedure allowing to obtain an ordered array of Ni nanowires that completely covering the surface of current collector made of the same material. Besides, by amperostatic deposition we have covered these electrode with nanoparticles of IrO2 elect…

Time-Dependent Density Functional Theory Calculations of N- and S-Doped TiO2 Nanotube for Water-Splitting Applications

2021

This research was funded by the Latvian Council of Science grant LZP-2018/2-0083. Institute of Solid State Physics, University of Latvia, as the Center of Excellence, has received funding from the European Union?s Horizon 2020 Framework Program H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under Grant Agreement No. 739508, project CAMART2.

Cerium oxyhydroxide nanowire growth via electrogeneration of base in nonaqueous electrolytes

2008

The preparation of compact cerium oxyhydroxide nanowires into anodic alumina membranes from cerium chloride in ethanol solution via electrogeneration of base is reported. Scanning electron microscopy analyses indicate that dense, well-aligned, and highly ordered nanowires can be formed in a wide range of applied potentials and current densities in alcoholic solution. The employment of water brings to a hybrid nanotube/nanowire structure, suggesting a key role of the electrolyte nature in determining the morphology of the deposit. Electrochemical findings and X-ray diffraction analysis have shown that nanowires are constituted by a Ce(III)/Ce(IV) oxyhydroxide that can be completely oxidized …

Enhancement of photoelectrochemical activity for water splitting by controlling hydrodynamic conditions on titanium anodization

2015

This work studies the electrochemical and photoelectrochemical properties of a new type of TiO2 nanostructure (nanosponge) obtained by means of anodization in a glycerol/water/NH4F electrolyte under controlled hydrodynamic conditions. For this purpose different techniques such as Scanning Electronic Microscopy (SEM), Raman Spectroscopy, Electrochemical Impedance Spectroscopy (EIS) measurements, Mott–Schottky (M−S) analysis and photoelectrochemical water splitting tests under standard AM 1.5 conditions are carried out. The obtained results show that electron–hole separation is facilitated in the TiO2 nanosponge if compared with highly ordered TiO2 nanotube arrays. As a result, nanosponges en…

Adsorption and photocatalytic degradation of acetonitrile: FT-IR investigation

2003

Abstract The photocatalytic degradation of acetonitrile was carried out in liquid–solid regime in a batch reactor by using two types of commercial TiO 2 powders (Merck and Degussa P25) as photocatalysts. The concentration of acetonitrile and non-purgeable organic carbon (NPOC) were monitored. The initial rate of acetonitrile conversion was found higher on TiO 2 Merck than on TiO 2 P25. FT-IR spectroscopy was used to investigate the molecular features of the adsorption and photo-oxidation of acetonitrile on the two TiO 2 powders in a fully surface hydrated form. Acetonitrile was found adsorbed on Ti 4+ surface ions and hydroxyl groups for both types of TiO 2 . This interaction appeared fully…

Saistvielu ietekme uz nātrija jonu bateriju katodmateriāla Na2/3MnO2 elektrodu virsmu un elektroķīmiskajām īpašībām

2022

Saistvielu ietekme uz nātrija jonu bateriju katodmateriāla Na2/3MnO2 elektrodu virsmu un elektroķīmiskajām īpašībām Krūze B., darba vadītājs Dr.phys. Kučinskis G. Maģistra darbs. 50 lappuses, 30 attēli, 1 tabula, 26 literatūras avoti, 2 pielikumi. Latviešu valodā. Maģistra darba ietvaros sintezēts Na2/3MnO2, no kura pagatavoti 3 veidu elektrodi, izmantojot dažādas saistvielas – polivinilidēnfluorīdu, nātrija alginātu un tetrabutilamonija alginātu. Elektrodiem tika analizētas elektroķīmiskās īpašības. Augstākā lādiņietilpība (164 mAh/g) un labākā ātrumspēja sasniegta ar tetrabutilamonija alginātu pagatavotiem elektrodiem, taču ciklējamība – ar nātrija alginātu. Pagatavotajiem elektrodiem tik…

Calibration of advanced Virgo and reconstruction of the gravitational wave signal h(t) during the observing run O2

2018

In August 2017, Advanced Virgo joined Advanced LIGO for the end of the O2 run, leading to the first gravitational waves detections with the three-detector network. This paper describes the Advanced Virgo calibration and the gravitational wave strain h(t) reconstruction during O2. The methods are the same as the ones developed for the initial Virgo detector and have already been described in previous publications, this paper summarizes the differences and emphasis is put on estimating systematic uncertainties. Three versions of the h(t) signal have been computed for the Virgo O2 run, an online version and two post-run reprocessed versions with improved detector calibration and reconstruction…