Department of Mineralogy, Petrography and Geochemistry Faculty of Geology, Geophysics and Environmental Protection AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków, Poland
Dr. Jakub Matusik
Department of Mineralogy, Petrography and Geochemistry Faculty of Geology, Geophysics and Environmental Protection AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków, Poland
Numerous adsorbents have been introduced to efficiently remove heavy metals and organic dyes from environmental water samples. However, magnetic a porous network aerogels are rarely developed to capture inorganic and organic pollutants from aqueous. We herein fabricated hexagonal boron nitride nanosheets (h-BNNSs)-based on magnetic hybrid aerogels (MHAs) as a lightweight adsorbent for robust uptake of Cr(VI), As(V), methylene blue (MB) and acid orange (AO). The synthetic procedure of poly(ethyleneimine)-modified h-BNNSs (PEI-h-BNNSs) involved thermal poly condensation of melamine and boric acid, pyrolysis of the resultant products which allowed exfoliated by ultra-sonication process further functionalization with PEI-mediated modification of h-BNNSs. The as formed PEI-h-BNNSs allowed in-situ formation of magnetite nanoparticles (Fe3O4 NPs) decorated on their surfaces, which are turned to be PEI-h-BNNSs@Fe3O4 NPs. The lyophilization treatment of PEI-h-BNNSs@Fe3O4 NPs-loaded PVA hydrogels generated the MHAs with large porous structures, diverse and numerous functional groups, good super-paramagnetic and a zero net surface charge. These features enabled the proposed adsorbent (MHAs) to be utilized to efficiently remove Cr(VI), As(V), MB, and AO from an aqueous solution, with maximum adsorption capacity estimated to be 833, 426, 415, 286 mg g−1, respectively. The adsorption kinetics and isotherm data demonstrated that MHAs mediated adsorption of Cr(VI), As(V), MB and AO followed the Freundlich isotherm model and a pseudo-second-order kinetics model. This finding signifies that the MHAs exhibit heterogeneous binding behavior with multilayer chemisorption of Cr(VI), As(V), MB and AO. Subsequently, the practical application were validated by conducting their detoxification of chromium and arsenic in soli-sludge samples.
Kaolin-group clay minerals can be modified to form nanotubular and mesoporous structures with interesting catalytic properties, but knowledge of the best methods for preparing these structures is still incomplete. The objective of this study was to investigate intercalation/deintercalation as a method for the delamination and rolling of kaolinite layers in relation to structural order. To prepare nanotubular material, kaolinites of different crystallinities and halloysite (all from Polish deposits) were chosen. The experimental procedure consisted of four stages: (1) preparation of a dimethyl sulfoxide precursor intercalate; (2) interlayer grafting with 1,3-butanediol; (3) hexylamine intercalation; and (4) deintercalation of amine-intercalated minerals using toluene as the solvent. Structural perturbations and changes in the morphology of the minerals were examined by X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, and transmission electron microscopy (TEM). The number of rolled kaolinite layers depended heavily on the efficiency of the intercalation steps. An increase in the structural disorder and extensive delamination of the minerals subjected to chemical treatment were recorded. Kaolinite particles which exhibited tubular morphology or showed rolling effects were observed using TEM. The nanotubes formed were ∼30 nm in diameter, with their length depending on the particle sizes of the minerals.