Facile synthesis of Fe₃O₄/MWCNTs by spontaneous redox and their catalytic performance

Abstract

Fe(3)O(4) nanoparticles with a size range of 4-8 nm were formed by the spontaneous redox reaction between Fe(3 + ) and multi-walled carbon nanotubes (MWCNTs). Cyclic voltammetry, Raman spectroscopy and x-ray photoelectron spectroscopy were employed to study the thermodynamic and dynamic conditions for the Fe(3)O(4)/MWCNTs formation. It is found that the high defect density of MWCNTs was thermodynamically favorable for the spontaneous reduction of Fe(3 + ) ions and a reaction time of above 2.5 h should be guaranteed. As the catalysts for benzene hydroxylation to phenol, the as-obtained Fe(3)O(4)/MWCNTs exhibit superior catalytic performance to those prepared by the hydrothermal method. Therefore, the spontaneous redox between the Fe(3 + ) and MWCNTs supplies an attractive facile route for the preparation of Fe(3)O(4) nanoscale catalysts.

Spontaneous selective deposition of iron oxide nanoparticles on graphite as model catalysts

“…There, electron rich carbon nanotubes donate electrons to Pt 2+ , Au 3+ , and Fe 3+ cations, reducing them upon selective deposition of Au, Pt and Fe 3 O 4 at the SWCNT defects. 9,63,64 For our study, the standard reduction potential of Fe 3+ to Fe 2+ is +0.771 V, a similar value to that observed for Au (HAuCl 4 ) and Pt (Na 2 PtCl 4 ). 65 Therefore, in the presence of a graphite surface in aqueous solution, Fe 2+ is susceptible to oxidation into Fe 3+ by water hydrolysis.…”

“…Previous studies found the correlation reduction potential of the Au(HAuCl 4 ), Pt(Na 2 PtCl 4 ), and Fe(NO 3 ) 3 precursors and whether deposition was spontaneous on carbon nanotubes. 9,65 The reduction potentials of AuCl 4…”

“…Iron oxide materials are commonly used in both industrial and laboratory scale for various applications because of their tunable catalytic, magnetic and electronic properties. 7,8 They are used in producing magnetic storage devices and magnetic ink for jet printing due to their tunable magnetic properties 9 as well as in medical applications such as biosensing, detoxication and drug delivery. 10 As earth-abundant heterogeneous catalysts, hematite (a-Fe 2 O 3 ) and magnetite (Fe 3 O 4 ) have their own unique properties depending on their oxidation state and crystallographic structure.…”

Electrodeposition of micro-nano size Fe3O4 crystals anchored on flexible buckypaper

“…The Fe 3 O 4 crystals tend to agglomerate into large clusters due to their high surface energy and spontaneous magnetization, which results in a loss of dispersity and effective surface area and therefore diminished catalytic activity [7]. By selecting an appropriate substrate, it is possible to stabilize and immobilize Fe 3 O 4 nanoparticles [8] and preserve their unique magnetic and catalytic properties.…”

Fabrication of graphene nanosheet (GNS)–Fe3O4 hybrids and GNS–Fe3O4/syndiotactic polystyrene composites with high dielectric permittivity

“…We quantitatively calculated the content of different carbon component based on the ratios of peak areas. As shown in Table 1, [24][25][26]. Moreover, the EDS result also revealed the existence of Fe and O elements in the hybrid (see Fig.…”