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Ni-Doped Graphene/Carbon Cryogels and Their Applications As Versatile Sorbents for Water Purification
journal contribution
posted on 2013-08-14, 00:00 authored by Gao Wei, Yue-E Miao, Chao Zhang, Zhe Yang, Zhenyan Liu, Weng Weei Tjiu, Tianxi LiuNi-doped
graphene/carbon cryogels (NGCC) have been prepared by adding resorcinol
and formaldehyde to suspension of graphene oxide (GO), using Ni2+ ions as catalysts for the gelation process to substitute
the usually used alkaline carbonates. The metal ions of Ni2+ have elevated the cross-linking between GO and RF skeletons, thus
strengthening the whole cryogel. The as-formed three-dimensional (3D)
interconnected structures, which can be well-maintained after freeze-drying
of the hydrogel precursor and subsequent carbonization under an inert
atmosphere, exhibit good mechanical properties. During the carbonization
process, Ni2+ ions are converted into Ni nanoparticles
and thus embedded in the interconnected structures. The unique porosity
within the interconnected structures endows the cryogels with good
capability for the extraction of oils and some organic solvents while
the bulk form enables its recycling use. When ground into powders,
they can be used as adsorbents for dyestuffs. Therefore, the as-obtained
cryogels may find potential applications as versatile candidates for
the removal of pollutants from water.