[Show abstract][Hide abstract] ABSTRACT: Iron and 1,3,5-benzenetricarboxylic (Fe–BTC) metal–organic coordination polymers are synthesized via a simple solvothermal method. The as-synthesized Fe–BTC polymers exhibit gel behavior, which is stable in common organic solvents or in water. The Fe–BTC polymer as an adsorbent for arsenic removal from water is tested. The kinetics and thermodynamics of arsenic adsorption by the Fe–BTC polymer in aqueous solution are investigated comprehensively. The effect of pH on the adsorption is also investigated. Kinetic studies show that the kinetic data are well described by the pseudo-second-order kinetic model. The thermodynamic analysis indicates that the adsorption is spontaneous. The adsorption isotherms can be well described with the Langmuir equation. The Fe–BTC polymers show relatively high arsenic adsorption capacity, more than 6 times that of iron oxide nanoparticles with a size of 50 nm and 36 times that of commercial iron oxide powders. Hence, the as-synthesized Fe–BTC polymers possess relatively high stability and better adsorption characteristic than nanomaterials simultaneously. It also can be considered as a new method to conquer the dilemma between the excellent properties from nanoscale effect and the aggregation of small size particles in the adsorption application of nanoparticle materials.
Full-text · Article · Apr 2012 · The Journal of Physical Chemistry C
[Show abstract][Hide abstract] ABSTRACT: Self-assembled, monodispersed, uniform, and flower-like γ-AlOOH hierarchical superstructures have been synthesized in high yield via a simple, economical and environmentally friendly, hydrothermal route. The product possesses a large BET surface area of 145.5 m2 g−1. It is found that Pb(II) and Hg(II) ions can be quickly removed from aqueous solutions by the flower-like γ-AlOOH. After only 5 min, the removal rate for Pb(II) and Hg(II) ions is over 99.0%. The maximal adsorption is ca. 124.22 mg g−1 for Pb(II) and 131.23 mg g−1 for Hg(II).
[Show abstract][Hide abstract] ABSTRACT: Fried egg jellyfish-like γ-AlOOH(Boehmite)@SiO2/Fe3O4 porous magnetic microspheres were synthesized by a simple template-induced method. The products were characterized by X-ray diffraction (XRD) analysis , scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray energy dispersive spectrometry (EDS), Fourier transform infrared spectroscopy (FTIR), nitrogen adsorption–desorption techniques and vibrating sample magnetometry (VSM). Influencing factors, such as the concentration of reactants, the reaction temperature and the reaction time, were systematically investigated. The adsorption properties of the fabricated sample were investigated for aqueous Pb(II) removal. The maximum adsorption capacity (qm) increased rapidly with an increasing void space in the shell of the microspheres, indicating that the void space is beneficial for increasing the adsorption properties of the material. The maximum adsorption capacity, qm = 214.59 mg g−1, is approximately 11.7-fold and 34.6-fold higher than SiO2/Fe3O4 and Fe3O4 magnetic microspheres, respectively. The adsorption isotherm fitted the Langmuir model well and the square of the correlation coefficient was r2 > 0.996. In addition, the effects of pH on the adsorption kinetics have also been investigated.
Full-text · Article · Oct 2011 · Journal of Materials Chemistry
[Show abstract][Hide abstract] ABSTRACT: O(2)-plasma-oxidized multiwalled carbon nanotubes (po-MWCNTs) have been used as an adsorbent for adsorption of lead(II) in water. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Raman spectroscopy measurements show that the bulk properties of MWCNTs were not changed after O(2)-plasma oxidation. The adsorption capacity of MWCNTs for lead(II) was greatly enhanced after plasma oxidation mainly because of the introduction of oxygen-containing functional groups onto the surface of MWCNTs. The removal of lead(II) by po-MWCNTs occurs rather quickly, and the adsorption kinetics can be well described by the pseudo-second-order model. The adsorption isotherm of lead(II) onto MWCNTs fits the Langmuir isotherm model. The adsorption of lead(II) onto MWCNTs is strongly dependent upon the pH values. X-ray photoelectron spectroscopy analysis shows that the adsorption mechanism is mainly due to the chemical interaction between lead(II) and the surface functional groups of po-MWCNTs. The thermodynamic parameters (ΔH°, ΔS°, and ΔG°) calculated from the adsorption isotherms suggest that the adsorption of lead(II) onto MWCNTs is endothermic and spontaneous. The regeneration performance shows that lead(II) can be easily regenerated from po-MWCNTs by altering the pH values of the solution.