Study On Preparation And Hydrogen Adsorption Properties Of Modified Graphene

Hydrogen energy storage is the most abundant and effective energy utilization system forhuman in the nature. As a new energy resource, it has been paid more and more attention fromthe world’s scientists. However, how to store hydrogen safely and efficiently has become abig problem for the widespread application. Carbon based materials become the hot researchpoint because of the unique structure and property. Graphene, a newly discovered carbonnano-materials, owns lots of advantages, such as, large special surface area，low atomic mess,chemical stability, abundant pore structure, wide source for raw materials. All of these areapplied widely into the field of hydrogen storage.Graphene has a large special surface area, theoretically, the uptake of hydrogen storage isin proportion to the specific surface area. However, it is very easy to aggregate among thegraphene nano-layers. Thus, the practical value of surface area is always lower than thetheoretical one, which makes it possible to explore appropriate methods to obtain stablegraphene suspension and to prepare high-quality of graphene with single layer for the purposeof increasing the hydrogen storage uptake.In this paper, graphene oxide was prepared by improved Hummers method andultrasonic, and then the graphene was obtained by using sodium borohydride to reduce theexfoliated graphite oxide, during which moderate sodium dodecyl benzene sulfonate(SDBS)was added into the suspension to reduce the agglomeration among graphene layers and obtaina stable graphene suspension. The as-prepared graphene was characterized by X-RayDiffraction (XRD), Raman Spectra (RS), X-ray Photoelectron Spectroscopy (XPS),Thermogravimetric(TG), Scanning Electron Microscope (SEM), Transmission ElectronMicroscope (TEM) and Atomic Force Microscope (AFM), N2adsorption-desorption. H2adsorption onto graphene was investigated under high pressure and the adsorption data weresimulated by the Langmuir and Freundlich equation. The results showed that Freundlichmodel can predict hydrogen molecules adsorbed on graphene nano-sheets better and majorphysisorption and few chemisorption happened between hydrogen molecule and graphene sheets.In addition, in the preparation of the graphene with the liquid oxidation-reductionmethod, the reduced reagent of glucose was researched, instead of the sodium borohydride. In order to maintain the basic solution, two drops of ammonia water were added into the reactionsolution. The as-prepared graphene was also characterized by XRD、SEM、TEM、FT-IR、Raman、XPS、TG、N2adsorption-desorption et al. The H2adsorption quantities wereresearched under atmosphere temperature and high pressure.Compared with the sample properties and the H2adsorption data from modified andunmodified graphene preparation method, it can be conducted that the surfactant and glucosecan provide means to prepare high-quality of graphene and to increase the hydrogen storageability.