Removal performance and mechanism of Fe3O4/graphene oxide as an efficient and recyclable adsorbent toward aqueous Hg(II)

Decontamination of aqueous heavy metal is a challenging task of environmental remediation. Herein, we demonstrated an adsorptive method for efficient removal of aqueous Hg(II) using a magnetic nanocomposite Fe₃O₄/graphene oxide (Fe₃O₄/GO). Adsorption of Hg(II) onto Fe₃O₄/GO equilibrated in 4 min, with the adsorption percent and quantity of 91.17% and 547.01 mg g^?1, respectively. Fe₃O₄/GO can be easily recovered from solution via magnetic separation for reuse, and retaining 73.5% of its original capacity after five consecutive cycles. The Temkin model and PSO model were most suitable for describing adsorption in equilibrium and non-equilibrium state, respectively. Both GO and Fe₃O₄ adsorbed Hg(II) via donating electrons in oxygen atoms toward Hg(II). Moreover, GO made a major contribution, while Fe₃O₄ made a minor one to adsorption. The facile preparation, high adsorption efficiency, easy recovery, and reusability may enable Fe₃O₄/GO to be a promising adsorbent for aqueous Hg(II).

     

Isomers of C24. Density functional studies including gradient corrections

Density functional techniques are used to investigate the relative energies of seven different structural isomers of C₂₄. The traditional local density approximation yields the fullerene-like isomer to be the most stable. As in the case of C₂₀, the inclusion of gradient corrections has a dramatic effect on the relative energies. The gradient-corrected B-LYP method yields the monocyclic ring and graphite-like isomers to be almost isoenergetic (and most stable) while the bicyclic ring, fullerene-like, and bowl-like isomers are progressively higher in energy. The Hartree—Fock results are quite similar to the B-LYP results. Implications to fullerene growth mechanisms are pointed out.     

Graphene oxide–starch composite as an efficient adsorbent for removing Cu(II): removal performance and adsorption mechanism

Research on Chemical Intermediates - Water pollution caused by heavy metals is a severe environmental issue. In this work, a graphene oxide–starch composite (GO/WS) was facilely prepared via...