The Influence of Laser Irradiation and Ultrasound on the Structure, Surface Condition and Electrical Properties of TiS[2]/C Composites

The structure, morphology and electroconductive properties of TiS2/C composite irradiated with laser and ultrasound are investigated in this work. It has been established that the conductivity of TiS2/C - 50/50 composite obtained by ultrasonic dispersion in acetonitrile at room temperature is 290 (Оhm∙m) – 1, which is in 10 higher than that value for pure titanium disulfide under the same conditions

Laser-modified nanocrystalline NiMoO4 as an electrode material in hybrid supercapacitors

The nanocrystalline NiMoO4 obtained as a result of hydrothermal synthesis was exposed to laser radiation with a pulse energy of 70 mJ/cm2 for 5 minutes. The phase composition and size of crystallites of the triclinic structure of NiMoO4 were determined by X-ray analysis. The average crystallite size was 18 nm for laser-irradiated nickel molybdate. Impedance analysis was used to analyze the temperature dependence of the electrical conductivity of laser-modified NiMoO4. The frequency index of the power law, determined by the nonlinear approximation method, was 0.5-0.67, which corresponds to the hopping mechanism of charge carriers. The electrochemical behavior of NiMoO4 was studied using cyclic voltammetry and galvanostatic charge/discharge testing. The laser-irradiated NiMoO4 reaches a specific capacitance of 553 F/g at a scan rate of 1 mV/s. The hybrid electrochemical system based on electrodes of modified NiMoO4 and carbon material provides high Coulombic efficiency (95%) for a significant number of charge/discharge cycles

Методика отримання та дослідження оптичних властивостей вуглецевих квантових точок.

The proposed method of synthesis of CQDs on the basis of nanoporous carbon obtained from plant raw materials. It is established that in the short-wave region a band is registered, which is due to the exciton mechanism of recombination, whereas in the long-wavelength region it is related to the state of defects. The kinetics of PL extinction is not strictly exponential, which most likely indicates the distributed nature of fading from individual emitters.Запропонована методика синтезу ВКТ на основі нанопористого вуглецю отриманого із рослинної сировини. Встановлено, що у короткохвильовій області реєструється смуга, зумовлена екситонним механізмом рекомбінації, тоді як у довгохвильовій області вона пов'язана станом дефектів. Кінетика згасання ФЛ не є строго експоненційною що найбільш ймовірно свідчить про розподілений характер згасання від окремих емітерів

Stimulation of the metal doping process of nanoporous carbon material by laser irradiation

It has been established that the doping of activated carbon material with chromium and manganese increases the specific capacitance of storage devices based on the charge-discharge mechanism of a double electric layer (DEL) by ~70 % and leads to a decrease in their internal resistance by 30-35 %. The main reason for this rise is the transformation of the electron energy spectrum due to an increase in the density of electronic states, as a result of which a much larger number of electrolyte ions (primarily positive ones) participate in the formation of DEL and cause an increase in the specific capacitance of these devices. It has been shown that laser irradiation stimulates the metal penetration into the bulk of carbon material

Interaction of electrolyte molecules with the surface of porous carbon: NMR study

Electrochemical double-layer capacitors use porous carbons as the electrode material, and improving their performance requires an understanding of the electrolyte−carbon surface interactions. 13C, 14N, and 11B NMR spectroscopy were used to investigate the behaviour of the electrolytes [C(OCH3)3NH3]+Cl- and [N(CH2CH3)]+BF4- on the surface of porous carbon in D2O solutions. A chemical shift of 13C has been found in the fragments N–C, indicating electron density redistribution between nitrogen atoms and alkyl fragments. The presence of a signal with a chemical shift of d = 7.7 confirms the structuring of the electrolytic layer of water solution [N(CH2CH3)]+BF4-