Ultrasmall α-Fe₂O₃ Superparamagnetic Nanoparticles with High Magnetization Prepared by Template-Assisted Combustion Process

Abstract

A template-assisted combustion-based method is developed to synthesize the ultrasmall (below 5 nm) α-Fe 2 O 3 nanoparticles. The iron and ammonium nitrate are used as oxidizers, glycine as a "fuel" and mesoporous silica (SBA-15) as a template. Because of the ultralow sizes and high crystallinity, the combustion-derived α-Fe 2 O 3 nanoparticles exhibit superparamagnetism in the temperature range of 70−300 K. The high specific surface area (132 m 2 /g) of α-Fe 2 O 3 indicates the important role of surface magnetic spins resulting in remarkably high magnetization (21 emu/g) at 300 K.

Magnetic iron nanoparticles prepared by solution combustion synthesis and hydrogen reduction

“…In view of these advantages, a large number of efforts have been made to prepare iron oxides by SCS [24][25][26][27]. Despite of such fascinating research results, to our knowledge, no research on hydrogen reduction of iron oxides by SCS has been reported.…”

Synthesis of Iron Oxide Nanorods Using a Template Mediated Approach

“…Compared to other template mediated synthesis of similar structures, the herein presented method allows the synthesis of particularly small and thin nanorods. [22][23][24] The corresponding histograms of diameter and length are displayed in Figure 1 C. Noticeably, the formation of the rod building template structure is not possible by purely adding the required amounts of water and ethanol to the reaction solution, after drying in high vacuum. Therefore, we conclude that the template formation needed for the nanorod formation can only take place during the iron oleate synthesis due to chemical reaction kinetics.…”

A Facile Fabrication of Supported Ni/SiO2 Catalysts for Dry Reforming of Methane with Remarkably Enhanced Catalytic Performance

“…When NH4NO3 is further added, NH3 and N2O can be formed via its decomposition at a low temperature of about 200 °C, thereby promoting combustion. The high-temperature stage in a short-duration favors the formation of ultra-small nanoparticles in a short time which may be in the order of seconds [40]. Figure 1d exhibits the reduction behavior of fresh Ni/SiO2 catalysts with different molar ratios of C2H5NO2 to NH4NO3.…”