Synthesis of porous single crystals of metal oxides via a solid-liquid route

Porous single crystals of Co3O4, NiO, CeO2, and Cr2O3 were produced using mesoporous silicas, SBA-15 and KIT-6, as hard templates and a new convenient approach, the solid-liquid method, was developed. Characterization of the materials was performed mainly by using X-ray powder diffraction and high-resolution transmission electron microscopy. The advantages and disadvantages of this solvent-free method are discussed in comparison with the previously established methods.