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Otrzymywanie i właściwości adsorpcyjne materiałów grafenowych

Szczęśniak B., Choma J., Jaroniec M.

Wiadomości Chemiczne

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2016

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[Z] 70, 3-4

189--217

EN

New, efficient and cost effective methods for CO2 capture are needed to keep the clean environment in the era of rising energy demand. Hydrogen is being considered as an ideal energy source for replacing fossil fuels. Since the breakthrough work in Science on graphene published in 2004 [22], this material has been intensively studied because of its great potential for applications in many fields of modern technology such as electronics [94–96], energy storage [21, 110, 111] and gas detection [13, 16]. As a two–dimensional, crystalline carbon material, graphene is characterized by superior chemicals and physical properties [2, 5]. The large theoretical specific surface area of graphene (2630 m2/g [89]) makes it an excellent material for adsorption applications. Furthermore, graphene– based materials could be doped by heteroatoms (e.g. B [72], N [106]) or decorated with various nanoparticles (e.g. Fe [55], Pd [106], Fe3O4 [8], V2O5 [79], TiO2 [79]), which significantly improves their adsorption properties. Specific mechanism CO2 [8] and H2 [104–106] takes place during adsorption processes on some graphene materials containing metal or metal oxide nanoparticles on their surfaces. In this review, the major methods for synthesis of graphene and graphene– based materials are discussed with particular emphasis on “chemical exfoliation”. The possibility of obtaining a high quality graphene material from waste materials such as polystyrene or biological materials such as crustacean skin [37, 41] is also reviewed. An overview of the newest synthesis methods of graphene [46] and modified graphene materials including polymer nanocomposites [61, 62] is presented too. A particular attention is given to CO2 and H2 adsorption properties of graphene– based materials [8, 62, 106]. Fe3O4 and Pd decorated graphene materials [8, 106–108] are ones of the most effective adsorbents described so far. These materials show a maximum CO2 adsorption capacity of 60 mmol/g at 25°C and 11 bar [8] and a maximum hydrogen uptake capacity of 4,4 wt% at 25°C and 40 bar [106]. It seems, that modified graphene materials can compete successfully with the currently used adsorbents, including nanoporous carbonaceous materials such as activated carbons, fullerenes, carbon nanotubes [8, 21] or ordered mesoporous carbon materials.

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Hydrogen adsorption study on lithium doped activated carbon

Łoś S., Duclaux L., Letellier M., Azais P.

Karbo

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2005

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Nr 4

252-256

EN

A volumetric method was applied to study an adsorption coefficient of hydrogen molecules in a gas phase on super activated carbon surface. The aim of the study is to get the best possible materials for the energy storage. Several treatments on raw samples were used to improve adsorption properties of carbon. The biggest capacities were obtained after high temperature treatment at reduced atmosphere. The adsorption coefficient at 77 K and 2 MPa amounts to 3.158 wt %. The charge transfer between lithium and carbon surface groups via the doping reaction enhanced the energy of adsorption. It was also found that there is a gradual decrease of the adsorbed amount of H2 molecules due to occupation active sites by lithium ions.

PL

Badano współczynnik adsorpcji wodoru cząsteczkowego w fazie gazowej na powierzchni super aktywowanego węgla metodą wolumetryczna. Ce-lern badania było uzyskanie możliwie najlepszych materiałów do magazynowania energii. Kilka sposobów obróbki surowych próbek zastosowano w celu polepszenia właściwości adsorpcyjnych węgla. Największe zdolności adsorpcji uzyskano po wygrzewaniu w wysokiej temperaturze przy obniżonym ciśnieniu. Współczynnik adsorpcji w 77 K i 2 MPa wynosił 3,158 % wag. Przeniesienie ładunku pomiędzy litem a grupami węglowymi na powierzchni przez domieszkowanie zwiększyło energię adsorpcji. Zauważono również stopniowy spadek ilości adsorbowanych molekuł Ii, w związku z zajmowaniem aktywnych miejsc przez jony litu.

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Pompowanie wodoru przez powierzchnię o niskiej temperaturze

Moraw M., Hałas A., Kirczuk C.

Elektronika : konstrukcje, technologie, zastosowania

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2001

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Vol. 42, nr 8-9

78-80

EN

Gas adsorption and condensation has been investigated in a vacuum system. With a large cold surface. The flux of water emerging from stainless steel surface has been measured. During the investigation of hydrogen adsorption, the sorption capacity and binding energy on the cold surface have been evaluated.