Hybrid nanocomposites based on Cu-BTC MOF, graphene oxide (GO), carbon nanotubes (CNTs), and Fe3O4 magnetic nanoparticles (MNPs) were developed via a simple green solvothermal method, at which GO and CNT were used as platforms to load nanostructured Cu-BTC MOF and Fe3O4 MNPs. The as-synthesized hybrid nanocomposites were characterized by XRD, SEM, TEM, XPS, IR, Raman, TGA, and BET techniques. XRD measurements show highly crystalline structures for the prepared hybrid nanocomposites. Morphological analyses carried out by SEM and TEM also confirm successful growth of Fe3O4 MNPs and nanoparticulate Cu-BTC MOF over the carbon-based platforms. Chemical, elemental, and TGA analyses verify chemical bonding and successful compositing of the parent materials. Nitrogen isotherms show a cumulative pore volume of 0.360 cm 3 g-1 for the hybrid nanocomposite of Fe3O4/Cu-BTC@GO compared to 0.030 cm 3 g-1 of the sole Cu-BTC MOF, which suggests potential uses towards small molecule adsorption. We have found that use of GO and CNT substrates (i) diminish the aggregation and increases dispersive forces within the MOFs, (ii) lead to MOFs with different morphology and size, and (iii) result in formation of small pores between the MOF and the platforms. Adsorption capacity of the prepared nanomaterials was examined over methylene blue (MB) as a model organic pollutant. The developed hybrid nanomaterials show enhanced pollutant adsorption capacity compared to that of the parent materials. The improved adsorption capacity is attributed to the synergetic effect of covalent bonding between the parent materials as well as to the unique features of the nanoscale MOF. Overall, these novel materials may be considered as excellent candidates towards a variety of environmental applications such as water remediation.

The chemical synthesis of gold nanoparticles (NP) by using gold (III) chloride trihydrate (HAuCl∙3H2O) and sodium citrate as a reducing agent in aqueous conditions at 100 °C is presented here. Gold nanoparticles areformed by a galvanic replacement mechanism as described by Lee and Messiel. Morphology of gold-NP was analyzed by way of high-resolution transmission electron microscopy; results indicate a six-fold icosahedral symmetry with an average size distribution of 22 nm. In order to understand the mechanical behaviors, like hardness and elastic moduli, gold-NP were subjected to nanoindentation measurements—obtaining a hardness value of 1.72 GPa and elastic modulus of 100 GPa in a 3–5 nm of displacement at the nanoparticle’s surface.

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Abstract:We present the chemical synthesis of hexaniobate nanotubes using two routes, (1) starting material K4Nb6O17 and (2) parent material of H4Nb6O17 via ion exchange. The as-synthesized materials were exfoliated by adjusting the pH to 9-10 using tetra-n-butylammonioum hydroxide (TBA + OH − ), leading to a formation of hexaniobate nanotubes. In order to understand morphology a full characterization was conducted using SEM, HRTEM, BET and powder-XRD. The photocatalytic activity was evaluated using photolysis method using Bromocresol Green (BG) and Methyl Orange (MO) as model contaminants. Results indicate a nanotube porous oxide with large porous and surface area; the photocatalytic activity is about 95% efficient when comparing with commercial TiO2.