Hybrid hematite/multi-walled carbon nanotube (α-Fe_2O_3/MWCNT) nanostructures as sorbents for Cu(II)

摘要

Hybrid α-Fe_2O_3/MWCNT nanostructures were prepared via the hydrolysis of ferric nitrate in the presence of MWCNTs. The amount of deposited α-Fe_2O_3, which influences the nanoparticle size and coverage density, was tuned during synthesis and the sorption capacity of the resulting nanomaterials was examined toward Cu(II) as a function of pH and metal concentration. Sorption is enhanced in hybrid nanostructure systems beyond what would be expected from simple additive sorption capacities of their building blocks. The enhanced sorption capacity is in part derived from the greater surface area of hematite nanoparticles immobilized on MWCNTs relative to aggregated hematite suspensions. The hybrid α-Fe_2O_3/MWCNT may also exhibit unique surface chemistry, as supported by the tunable values of zeta potential measured as a function of the mass of α-Fe_2O_3 deposited on the MWCNTs.