Nitrogen adsorption on graphene sponges synthesized by annealing a mixture of nickel and carbon powders

The present research has been supported by the National Research Programme for 2014–2017 “Multifunctional Materials and Composites, Photonics and Nanotechnologies”.Adsorption by graphene sponge (GS) manufactured by annealing nickel-carbon powder mixture in inert atmosphere has been studied. By determining the specific surface area (SSA) for the GS sample, it has been found that Brunauer, Emmett, Teller method (BET) of approximation of experimental isotherms gives wrong results in the pressure range of 0.025-0.12 because adsorption in this pressure region is affected by walls of ampoule. Real SSA value has been found by subtracting pore effect method (SPE) or by BET approximation in a low range of relative pressure of 0.0004-0.002.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

Content and Properties of Mechanically Sorted Municipal Wastes and Their Suitability for Production of Alternative Fuel

Abstract. The article presents the results of experimental work in the first waste mechanical Pre-treatment Centre in Latvia. The goal -to detect the main parameters for separated waste parts and to compare them with parameters stated for alternative fuels in cement plant in Latvia. Samples were taken in three fractions -coarse, medium, and fine. 132 samples have been taken. The parameters -upper, lower heating values, moisture, ash content, S, Cl, metals were determined. Resultscoarse fraction has greater potential of the production of the alternative fuel

Nitrogen Adsorption by Thermoexfoliated Graphite

Adsorption by thermochemically exfoliated graphite (TEG) is studied and compared with that by other carbon structures under the same conditions. In BET determination of the specific surface area (SBET) for the TEG samples it was found that good approximation could be observed in two different pressure ranges. Such ranges of BET approximation are also visible in the isotherms of aquadag and milled graphite. The experimental results are discussed and their interpretation proposed

Graphene Nanosheets Grown on Ni Particles

Ultrathin graphite sheets or/and graphene nanosheets were obtained on the surface of particles of Ni powder. The new method based on well known dissolution and precipitation mechanism of graphene formation on catalyst surface is reported. Fig.1a presents the Ni powder particles with as prepared graphene sheets. Graphene nanosheets can be seen on the surface of Ni beads as grey coating on light beads. Freestanding graphene sheets were obtained after dissolution of Ni. Upon dissolution of the Ni powder is possible disintegration of the coating into the individual graphene sheets or the graphene sheets are formed the carbon body in the form of the original ingot sintered powder of Ni. In the first case graphene samples were obtained by vacuum filtration, in the second after drying of carbon body. SEM images (Fig. 1b) revealed that surface of the bodies consist of randomly aggregated, crumpled sheets closely associated with each other. The thickness of these sheets was determined with XRD by (002) diffraction peak broadening (Fig. 3). The quality of the sheets was estimated by Raman scattering spectra. Obtained by us layers can be defined as a graphene nanosheets. Number of graphene monolayers in these nanosheets controllably varied from 7 to 40