Synthesis, structural and chemical properties of iron oxide–silica aerogelsElectronic supplementary information (ESI) available: cumulative pore volumes and t-plots of the calcined aerogels prepared by different sol–gel methods, and of aerogels with different iron loadings. See http://www.rsc.org/suppdata/jm/b1/b108120a/

Magnetic and Mössbauer spectroscopy studies of nanocrystalline iron oxide aerogels

“…As demonstrated previously, 6 a 260°C heat treatment of the as-prepared FeOx aerogels under argon flow ͑sample 260-ARG͒ yields nanocrystalline structures with crystallite sizes of ϳ7 nm ͓see Fig. 1͑A͔͒.…”

“…6 Thermal treatments were performed in either static ambient air or flowing argon ͑linear flow rate= 56 cm min −1 ͒ to convert the amorphous as-prepared FeOx aerogels to nanocrystalline forms. The various samples are labeled according to their thermal treatments: "260-ARG" denotes as-prepared FeOx aerogels heated under argon flow at 260°C and "260-ARG-AIR" is used to denote the 260-ARG aerogel after an additional heat treatment at 260°C in static air.…”

“…Magnetic iron oxides, such as ␥-Fe 2 O 3 ͑maghemite͒ or Fe 3 O 4 ͑magnetite͒, have been incorporated into SiO 2 aerogel matrices, combining the desirable structural characteristics of the aerogel with magnetic properties of the iron oxide. [1][2][3][4][5][6][7][8] Recently, Long et al 6 adapted a highly flexible sol-gel method to prepare freestanding FeOx aerogels with the specific goal of generating magnetic aerogel nanoarchitectures. Controlled temperature/ atmosphere treatments were applied to convert the amorphous as-prepared FeOx aerogels into mixed-phase nanocrystalline Fe 3 O 4 / ␥-Fe 2 O 3 forms, with the specific crystalline phase being highly dependent on the atmosphere ͑inert versus oxidizing͒ used during the crystallization.…”

Silica aerogel–iron oxide nanocomposites: recoverable catalysts for the oxidation of alcohols with hydrogen peroxide

“…For the sample 3, the broad peak at 2h = 21-278 is typically characteristic of amorphous silica. No evidence indicated the presence of maghemite or magnetite phases [41]. Empirically, iron oxide made from an alkoxide precursor similar in nature to the one we used exhibits a hematite phase at 500°C as determined by XRD analysis [42].…”

Iron oxyhydroxide aerogels and xerogels by controlled hydrolysis of FeCl3·6H2O in organic solvents: stages of formation

“…their moderate stiffness is combined with very high specic surface area and low density. 4,5 They can be used as substances with special magnetic properties, 6-8 as catalysts 9,10 or as precursors of specic reagents (Al/Fe 2 O 3 ) 11 or as heat insulators. 5 Furthermore, oxyhydroxide gels can also be used for water remediation.…”