Fabrication of Mesoporous Co3O4 from LP-FDU-12 via Nanocasting Route and Effect of Wall/Pore Size on Their Magnetic Properties

Highly ordered mesoporous Co3O4 nanostructures were prepared using LP-FDU-12 as hard templates. By changing the hydrothermal temperature or by the acid treatment of the LP-FDU-12 template, Co3O4 replicas with different cell parameters and wall thicknesses have been obtained. The structure and textural characteristics of both LP-FDU-12 and Co3O4 replicas were investigated by X-ray diffraction, transmission electron microscopy, and N-2 adsorption-desorption isotherm analysis. The cell parameter and wall thickness of a mesoporous Co3O4 have been varied systematically within the ranges 30.4-33.9 and 24.8-18.2 nm, respectively, and the materials exhibit surface areas in the 29.6-52.9 m(2) g(-1) range, while preserving a highly ordered 3D pore structure and highly crystalline walls. Most importantly, magnetic studies show that the factors which affect the magnetic behavior in the Co3O4 nanosphere system are not only the sphere size but also the space-filled parameter at the nanoscale.