One-step chemical vapor deposition synthesis of magnetic CNT–hercynite (FeAl2O4) hybrids with good aqueous colloidal stability

NOE´ J. MORALES A, SILVIA GOYANES B, CLAUDIO CHILIOTTE C, VICTORIA BEKERIS C, ROBERTO J. CANDAL A,D, GERARDO H. RUBIOLO B,E,*

CARBON

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2013

0008-6223

A multiwall carbon nanotube (MWCNT)/hercynite (FeAl2O4) hybrid nanomaterial was synthesizedby one-step chemical vapor deposition (CVD) using acetylene as precursor andFeOx–AlOOH xerogel as catalyst. The hybrid material was composing by hercynite nanoparticles(diameter 10–50 nm) intimately attached to the walls of the MWCNTs. The diameterof the MWCNTs was related to particle size of the catalyst. The hybrid nanomaterial exhibiteda characteristic magnetic behavior that can be considered as a combination of superparamagnetismand ferromagnetism, with a saturation magnetization of 5.7 emu/g at anapplied field of 18 kOe and a coercivity of 520 Oe. The hybrid displayed a relatively lowpHZPC (approx. 3.2) and formed very stable aqueous suspensions at pH 5.5. Controlled oxidationof the hybrid generated oxidized functional groups, as –OH and –COOH, and promotedthe transformation of hercynite to hematite. Due to the high dispersibility of thehybrid in water, it presents an interesting potential as nanofiller for hydrophilic polymers.