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

Highly ordered mesoporous Co 3 O 4 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, Co 3 O 4 replicas with different cell parameters and wall thicknesses have been obtained. The structure and textural characteristics of both LP-FDU-12 and Co 3 O 4 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 Co 3 O 4 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 Co 3 O 4 nanosphere system are not only the sphere size but also the space-filled parameter at the nanoscale.