Layered double hydroxides (LDHs) show great potential as CO 2 adsorbent materials, but require improvements in stability and CO 2 adsorption capacity for commercial applications. In the current study, graphene oxide provides a light-weight, chargecomplementary, two-dimensional (2D) material that interacts effectively with the 2D LDHs, in turn enhancing the CO 2 uptake capacity and multicycle stability of the assembly. As a result, the absolute capacity of the LDH was increased by 62% using only 7 wt % graphene oxide (GO) as a support. The experimental procedure for the synthesis of the materials is based on a direct precipitation of the LDH nanoparticles onto GO followed by a structural and physical characterization by electron microscopy, X-ray diffraction, thermogravimetric analysis, and Brunauer−Emmett− Teller (BET) surface area measurements. Detailed titration confirmed the compatibility of the surface chemistry. After thermal decomposition, mixed metal oxides (MMOs) are obtained with the basic sites required for the CO 2 adsorption. A range of samples with different proportions of GO/MMO were prepared, fully characterized, and correlated with the CO 2 sorption capacity, established via TGA.

Layered double hydroxides (LDHs) are promising materials for CO 2 sorption, although improvements in performance are required for practical applications. In the current study, the CO 2 sorption capacity and multi-cycle stability were both increased by introducing an open supporting framework of multiwalled carbon nanotubes (MWNTs). This nanostructured inert network provides a high surface area, maximizing the gas accessibility and minimizing coarsening effects. Specifically, LDH nanoparticles were precipitated directly onto MWNTs, initially oxidised to ensure a favourable electrostatic interaction and hence a good dispersion. The dependence of the structural and physical properties of the Mg-Al LDH grown on MWNT supports has been studied, using electron microscopy, X-ray diffraction, thermogravimetric analysis (TGA), and BET surface area, and correlated with the CO 2 sorption capacity, established via TGA and temperature programmed desorption measurements. The use of a MWNT support was found to improve the absolute capacity and cycle stability of the hybrid adsorbent under dry conditions.

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Lithium metal can be used to reduce single-walled carbon nanotubes (SWNT) to carbide-like species under the catalytic effect of di-tert-butyl-biphenyl (DTBP). The resulting nanotube polycarbanions show a significantly increased dispersability in THF and react "in situ" with trimethylchlorosilane, methyl methacrylate, and methyl N-acetamidoacrylate to afford covalently functionalized silyl nanotubes and polymer-wrapped SWNT. The density and average length of the polymer chains attached to the nanotube wall can be widely modified by varying the amount of monomer, lithium, and catalyst.