Two-step synthesis of Fe₂O₃and Co₃O₄nanoparticles: towards a general method for synthesizing nanocrystalline metal oxides with high surface area and thermal stability

Abstract

A simple, two-step method using activated carbon (AC) as a support/scaffold was developed to synthesize metal oxide nanocrystalline materials (NCMs). In the first step, metal nitrate precursors were deposited by wet impregnation onto the AC, then heated in argon at 350 uC to immobilize the metal oxides. In the second step, the AC was removed by calcination in air at 500 uC, to obtain the unsupported metal oxide NCMs. Characterization by N 2 -sorption isotherms, TGA, XPS and EXAFS reveals that the metal oxide particles are crystalline and nanometre-sized, with surface areas up to 148 m 2 g 21. Moreover, the TEM images show particle sizes in the range 5-10 nm, even after calcination at 500 uC for 2 h. Their thermal stability and high surface areas, together with the nanometre-sized structures, make them promising materials for catalytic applications (e.g., CO oxidation).

Controlled synthesis and characterization of electron rich iron(iii) oxide doped nanoporous activated carbon for the catalytic oxidation of aqueous ortho phenylene diamine

“…Thereaer, weight losses of 8.63% and 17.81% were observed at 216 C and 537 C respectively, this could be due to the gasication of the chemical deposit contributed by the pre-treatment process. 51 This was followed by a weight loss of 27.06% up to 800 C and the residue le was 9.8 mg from the initial mass of 13.41 mg. Heterogeneous Fenton oxidation of OPD using Fe-NPAC 400 as catalyst Effect of hydrogen peroxide on catalytic oxidation of OPD by Fe-NPAC 400 . Hydrogen peroxide plays the role of an oxidizing agent in the heterogeneous Fenton reaction.…”

Metal Oxides and Oxysalts as Anode Materials for Li Ion Batteries

“…A critical assessment of anodic behavior of Co 3 O 4 is described in a recent review by Cabana et al The interested reader may refer to the various references therein. Additional recent studies on the Li cycling of bare Co 3 O 4 , and carbon– and graphene–Co 3 O 4 composites are given in refs , , , , and − , and capacity values are summarized in Table .…”

Pure and multi metal oxide nanoparticles: synthesis, antibacterial and cytotoxic properties

“…Highly monodisperse nanostructures with enhanced activities, uniform morphology and a high specific surface area can be obtained using this synthesis method [ 142 ]. Examples are mesoporous MoO 2 nanoparticles with improved electrochemical properties [ 143 ], α-Fe 3 O 4 and Co 3 O 4 [ 144 ], Fe 2 O 3 [ 145 ] and mesoporous NiMn 2 O x [ 144 ]. The templates used for such synthesis methods mainly are track-etch membranes, porous alumina and other nanoporous structures, like mesoporous zeolites [ 146 , 147 ].…”