title: Ni-doped graphene/carbon cryogels and their applications as versatile sorbents for water purification.
abstract: Ni-doped graphene/carbon cryogels (NGCC) have been prepared by adding resorcinol and formaldehyde to suspension of graphene oxide (GO), using Ni(2+) ions as catalysts for the gelation process to substitute the usually used alkaline carbonates. The metal ions of Ni(2+) 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, Ni(2+) 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.
authors.affiliation: State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200433, P. R. China.
authors.forename: Gao
authors.initials: G
authors.lastname: Wei
authors.forename: Yue-E
authors.initials: YE
authors.lastname: Miao
authors.forename: Chao
authors.initials: C
authors.lastname: Zhang
authors.forename: Zhe
authors.initials: Z
authors.lastname: Yang
authors.forename: Zhenyan
authors.initials: Z
authors.lastname: Liu
authors.forename: Weng Weei
authors.initials: WW
authors.lastname: Tjiu
authors.forename: Tianxi
authors.initials: T
authors.lastname: Liu
mesh_terms: D000327:Adsorption; D002244:Carbon / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry; D059985:Cryogels / Q000737:chemistry*; D005557:Formaldehyde / Q000737:chemistry; D006108:Graphite / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry; D008855:Microscopy, Electron, Scanning / Q000379:methods; D009532:Nickel / Q000737:chemistry*; D009821:Oils / Q000737:chemistry; D010087:Oxides / Q000737:chemistry; D012118:Resorcinols / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013314:Stress, Mechanical; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods*
chemical_list: D004396:Coloring Agents; D059985:Cryogels; D020100:Hydrogels; D009821:Oils; D010087:Oxides; D012118:Resorcinols; D014874:Water Pollutants, Chemical; D005557:Formaldehyde; D002244:Carbon; D006108:Graphite; D009532:Nickel; C031389:resorcinol