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Sabina Elżbieta Drewniak, Tadeusz Piotr Pustelny, Roksana Muzyka and Agnieszka Plis

LITERATURE CITED 1. Eda, G. & Chhowalla, M. (2010). Chemically derived graphene oxide: towards large-area thin-film electronics and optoelectronics. Adv. Mater. 22(22), 2392–2415. DOI: 10.1002/adma.200903689. 2. Stankovich, S., Dikin, D.A., Piner, R.D.,. Kohlhaas, K.A., Kleinhammes, A., Jia, Y., Wu, Y., Nguyen, S.T. & Ruoff, R.S. (2007). Synthesis of graphene-based nanosheets via chemical reduction of exfoliated graphite oxide. Carbon 45(7), 1558–1565. DOI:10.1016/j.carbon.2007.02.034. 3. Wong, C., Jankovsky, O., Sofer, Z. & Pumera, M. (2014

Open access

Łukasz Majchrzycki, Monika Michalska, Mariusz Walkowiak, Zbigniew Wiliński and Ludwika Lipińska

.07.039. 15. Bak S.M. et al. (2011). Spinel LiMn2O4/reduced graphene oxide hybrid for high rate lithium ion batteries. J. Mater. Chem. 21, 17309-17315. DOI: 10.1039/C1JM13741G. 16. Wan Ch., Nuli Y., Zhuang J., Jiang Z. (2002). Synthesis of spinel LiMn 2 O 4 using direct solid state reaction. Materials Letters 56, 357-363. DOI: 10.1016/S0167-577X(02)00485-8. 17. Zhang, X. et al. (2011). Electrochemical performance of spinel LiMn 2 O 4 cathode materials made by flame-assisted spray technology. J. Power Sources 196, 3640-3645. DOI: 10

Open access

Anna Trusek

LITERATURE CITED 1. Zhen, Z. & Zhu H. (2017). Structure and Properties of Graphene , Academic Press. 2. Wang, Y., Li, Z., Wang, J., Li, J. & Lin, Y. (2011). Graphene and graphene oxide: biofunctionalization and applications in biotechnology. Trends Biotechnol . 29(5), 205–212. DOI: 10.1016/j.tibtech.2011.01.008. 3. Talat, M. & Srivastava, O.N. (2016). Deployment of New Carbon Nanostructure: Graphene for Drug Delivery and Biomedical Applications, Advances in Nanomaterials 383–395, DOI: 10.1007/978-81-322-2668-0_11 4. Lin, L.L., Chi, M

Open access

P. Kula, W. Szymański, Ł. Kołodziejczyk, R. Atraszkiewicz, K. Dybowski, J. Grabarczyk, R. Pietrasik, P. Niedzielski, Ł. Kaczmarek and M. Cłapa

In this work, the growth mechanisms of chemical vapor deposited and metallurgical graphene and their selected mechanical and electrical properties were investigated. The study revealed the influence of the growth mechanisms on monoand poly-crystalline nanostructures of synthesized graphene monolayers. The structure of flake boundaries greatly affects both the mechanical and electrical properties. The key factors are overlapping of the graphene flakes, their degree of mismatch and the presence of π type bonds. All of these issues should be taken into account when developing industrially scaled technologies for graphene manufacturing.

Open access

Izabela Kondratowicz, Kamila Żelechowska, Dominika Majdecka and Renata Bilewicz

Abstract

We have carried out the preparation of reduced graphene oxide aerogels using eco-friendly method that is based on the Hummers method of graphite oxidation without the use of NaNO3 that produces toxic gases. To obtain a porous 3D structure of reduced graphene oxide, we performed the hydrothermal reduction at elevated temperature. We also prepared the rGO aerogel/CNT composite using multiwalled carbon nanotubes as linkers. The rGO aerogels are promising materials as they possess good electrical conductivity (up to 100 S/m) and high surface area and porous structure (~500 m2/g). The main goal was to obtain the material for electrodes in enzymatic biofuel cells. Thus, the proper modification was performed using free radical functionalization. It was shown that in order to synthesize rGO aerogels modified with anthracene, the proper order of reactions needs to be provided. The morphology of anthracene modified electrodes was analyzed using scanning electron microscopy, which confirmed their porous structure with non-uniform pore size distribution that ranged between few nanometers to microns. Data obtained by Raman spectroscopy confirmed the successful oxidation and reduction of analyzed materials. UV-Vis spectra revealed the presence of anthracene moieties in examined materials. We also recorded preliminary cyclic voltammograms that confirm an electric conductivity of the obtained structures.

Open access

P. Duda, R. Muzyka, Z. Robak and S. Kaptacz

Abstract

Due to their characteristics, sintered Cu-C composites are materials used in electrical equipment. These characteristics include high electrical conductivity, thermal conductivity and excellent resistance to abrasion. Currently, graphite nanopowder is used successfully as a carbon material. Metal-graphite, which is created on its basis, exists in different proportions of graphite to metal. A larger graphite content has a positive effect on smaller wear of commutators and rings. In contrast, a material with a higher copper content is used at high current densities. An example of such machines is a DC motor starter characterized by low voltage and large current.

Tribological properties of Cu-C composites depend on the form of carbon they include. Owing to the capability to manufacture graphene, it has become possible to produce composites with its content. The present study tested the effect of a graphene oxide content on tribological properties in contact with steel. Tests were conducted on a ball-on-disk apparatus in conditions of dry friction. Microscopic observation was performed on the Hitachi SU70 field emission electron microscope. EDS analyses were performed using the Thermo Scientific X-ray Microanalysis system. Disk wear and surface geometrical structure parameters (SGP) of the samples after tribological tests were determined on the basis of measurements made on the Talysurf 3D contact profilometer from Taylor Hobson.

Open access

M. Wojtoniszak, B. Zielinska, R. Kalenczuk and E. Mijowska

Abstract

In this paper, we present a study on enhanced photocatalytic performance of TiO2 nanospheres deposited on graphene (n-TiO2-G) in a process of coumarin oxidation. The enhancement of the photoactivity has been observed in respect to commercial TiO2 P25. The presented material was prepared in two steps: (i) hydrolysis of titanium (IV) butoxide (TBT) in ethanol solution with simultaneous deposition on graphene oxide (GO) and (ii) calcination of TiO2-GO to form anatase-TiO2 and reduce GO to graphene. The nanomaterial was characterized by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), thermogravimetric analysis (TGA), Fourier-Transformed Infrared spectroscopy and Raman spectroscopy. In the presented photocatalytic process the fluorescence was used to detect •OH formed on a photo-illuminated n-TiO2-G surface using coumarin which readily reacted with •OH to produce highly fluorescent 7-hydroxycoumarin.

Open access

E. Dikio, F. Thema, A. Farah and N. Shooto

Abstract

The functionalized graphene (GO) was fabricated by a simple method of chemical reduction in a polar aprotic solvent. This paper therefore, describes a versatile and synthetic route for the preparation of reduced graphene oxide (RGO) and its behavior when exposed to magnetic field environment. The characterization results of transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy and the attenuated total reflectance-Fourier transform infra-red (ATR-FTIR) analysis indicate that graphite was exfoliated and reduced to graphene layers.

Open access

V. Grehov, J. Kalnacs, A. Mishnev and K. Kundzins

REFERENCES 1. Novoselov, K.S., Geim, A.K., Morozov, S.V., Jiang, D., Zhang, Y., Dubonos, S.V., et al. (2004). Electric field effect in aAtomically thin carbon films. Sci 2004 :306, 666–9. 2. Batzill, M. (2012). The surface science of graphene: Metal interfaces, CVD synthesis, nanoribbons, chemical modifications, and defects. Surface Science Reports 2012 : 67, 83–33. 3. Singh, V., Joung, D., Zhai, L., Das, S., Khondaker, S.I., and Seal, S. (2011). Graphene based materials: Past, present and future. Progress in Materials Sci 2011 :56, 1178

Open access

S. Piskunov, Y. F. Zhukovskii, M. N. Sokolov and J. Kleperis

Abstract

Substitution of fossil-based chemical processes by the combination of electrochemical reactions driven by sources of renewable energy and parallel use of H2O and CO2 to produce carbon and hydrogen, respectively, can serve as direct synthesis of bulk chemicals and fuels. We plan to design and develop a prototype of electrochemical reactor combining cathodic CO2-reduction to ethylene and anodic H2O oxidation to hydrogen peroxide. We perform ab initio calculations on the atomistic 2D graphene-based models with attached Cu atoms foreseen for dissociation of CO2 and H2O containing complexes, electronic properties of which are described taking into account elemental electrocatalytical reaction steps. The applicability of the model nanostructures for computer simulation on electrical conductivity of charged Cun/graphene (0001) surface is also reported.