Diffraction efficiency of a small-period astronomical x-ray reflection grating fabricated using thermally activated selective topography equilibration

ABSTRACTWe report here the results of our study on the properties of iodine-doped C60 thin films by IR and optical absorption, X-ray diffraction, and electrical conductivity measurements. The results show that there is no apparent structural change in the iodine-doped samples at room temperature in comparison with that of the undoped films. However, in the electrical conductivity measurements, an increase of more that one order of magnitude in the room temperature conductivity has been observed in the iodine-doped samples. In addition, while the conductivity of the undoped films shows thermally activated temperature dependence, the conductivity of the iodine-doped films was found to be constant over a fairly wide temperature range (from 20°C to 70°C) exhibiting a metallic feature.

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Photocatalytic Degradation of 2,4,6-Trichlorophenol by MgO–MgFe2O4 Derived from Layered Double Hydroxide Structures

Catalysts ◽

10.3390/catal9050454 ◽

2019 ◽

Vol 9 (5) ◽

pp. 454 ◽

Cited By ~ 5

Author(s):

Esthela Ramos-Ramírez ◽

Francisco Tzompantzi-Morales ◽

Norma Gutiérrez-Ortega ◽

Héctor G. Mojica-Calvillo ◽

Julio Castillo-Rodríguez

Keyword(s):

Photocatalytic Degradation ◽

Layered Double Hydroxides ◽

X Ray Diffraction ◽

Application Study ◽

Toxic Compounds ◽

X Ray ◽

Thermally Activated ◽

Double Hydroxide ◽

Double Hydroxides ◽

Scanning Electron

In recent years, the search for solutions for the treatment of water pollution by toxic compounds such as phenols and chlorophenols has been increasing. Phenols and their derivatives are widely used in the manufacture of pesticides, insecticides, paper, and wood preservers, among other things. Chlorophenols are partially biodegradable but not directly photodegradable by sunlight and are extremely toxic—especially 2,4,6-trichlorophenol, which is considered to be potentially carcinogenic. As a viable proposal to be applied in the treatment of water contaminated with 2,4,6-trichlorophenol, this paper presents an application study of the thermally activated Mg/Fe layered double hydroxides as photocatalysts for the mineralization of this contaminant. Activated Mg/Fe layered double hydroxides were characterized by X-ray diffraction, thermal analysis, N2 physisorption, and scanning electron microscopy with X-ray dispersive energy. The results of the photocatalytic degradation of 2,4,6-trichlorophenol in aqueous solution showed good photocatalytic activity, with an efficiency of degradation of up to 93% and mineralization of 82%; degradation values which are higher than that of TiO2-P25, which only reached 18% degradation. The degradation capacity is attributed to the structure of the MgO–MgFe2O4 oxides derived from double laminate hydroxide Mg/Fe. A path of degradation based on a mechanism of superoxide and hollow radicals is proposed.

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High-Capacity Derivatives Produced from Hydrolytic Lignin as Electrode Materials for Energy Storage and Conversion

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.386.359 ◽

2018 ◽

Vol 386 ◽

pp. 359-364

Author(s):

Yury M. Nikolenko ◽

Denis P. Opra ◽

Alexander K. Tsvetnikov ◽

Alexander Yu. Ustinov ◽

Valery G. Kuryavyi ◽

...

Keyword(s):

Electron Microscopy ◽

Energy Storage ◽

Electrode Materials ◽

Electronic Conductivity ◽

Specific Capacity ◽

Energy Storage And Conversion ◽

Operating Voltage ◽

X Ray ◽

Thermally Activated ◽

Hydrolytic Lignin

The hydrolytic lignin derivatives have been prepared via its physical activation (high-temperature heating in vacuum) followed by chemical modification (fluorination). The obtained products were characterized using scanning electron microscopy, X-ray diffraction, transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. It was found that the graphitized product of thermal activation up to 1000 °C at a low rate of < 2 °C/min under high vacuum shows an enhanced specific surface area (215 m2/g), that makes its potentially useful as sorbent, catalytic substrate or electrode material. To clarify the potentialities of hydrolytic lignin derivatives for energy storage and conversion, the electrochemical system with metallic lithium anode was applied. The galvanostatic discharge of battery at a current density of 100 μA/cm2between 3.0 and 0.5 V shows that the specific capacity of thermally activated derivative is equal to 845 mA·h/g, while the untreated lignin yields only 190 mA·h/g. The improve of the electrochemical performance of product originates from its graphitization, increasing electronic conductivity, and, possibly, enhanced ability to adsorb of oxygen. The fluorination of both the lignin and its thermally activated form results in higher operating voltage of battery, as seems, due to the involvement of fluorine bound to carbon in electrochemical process.

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Thermally Induced Superlow Friction of DLC Films in Ambient Air

High Temperature Materials and Processes ◽

10.1515/htmp-2017-0045 ◽

2018 ◽

Vol 37 (8) ◽

pp. 725-731 ◽

Cited By ~ 4

Author(s):

Qunfeng Zeng

Keyword(s):

Photoelectron Spectroscopy ◽

Ambient Air ◽

Friction Model ◽

Repulsive Force ◽

Hydroxyl Group ◽

Thermally Induced ◽

X Ray ◽

Thermally Activated ◽

Charged Interface ◽

Positively Charged

AbstractThermally induced superlow friction (0.008) of diamond-like carbon (DLC) films was achieved in ambient air in the present work. Raman and XPS (X-ray Photoelectron Spectroscopy) measurements and analyses show that superlow friction of the annealed DLC films is involved in the transformation of sp3 to sp2 hybridized carbon during annealing and the tribochemical reactions during sliding. The thermally activated graphitization and oxidation of the annealed DLC films in ambient air is beneficial to form the positively charged interface and achieve the stable superlow friction. A friction model was developed and applied to explain superlow friction, which is attributed to Van de Waals force between graphite layers and the repulsive force between hydroxyl group of graphite oxide and hydrogen terminated DLC films surface.

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