Uniform cerium-based metal–organic framework microflowers: controlled synthesis, characterization and formation mechanism

Three dimensional (3D) flower-like cerium pyrazine-2,3,5,6-tetracarboxylate metal–organic framework has been successfully prepared on a large scale through a simple and facile hydrothermal method without the assistance of any surfactant or template. The composition and structure of the samples were well characterized by Fourier transform infrared spectroscopy, X-ray powder diffraction, elemental analysis, thermogravimetric analysis, scanning electron microscopy, and energy dispersive X-ray, respectively. The experimental results indicate that these 3D flower-like architectures with diameter of about 4 μm are composed of a large number of nanosheets. The presumed molecular formula of the cerium-based metal–organic framework is Ce2(pztc)(H2O)6. In addition, a possible mechanism for the formation of cerium pyrazine-2,3,5,6-tetracarboxylate architectures was proposed based on time-dependent experiments. Furthermore, the as-obtained flower-like cerium-based metal–organic framework architectures could be easily transformed into CeO2 microstructures with flower-like outlines through simply heat-treating in air.