Hierarchical Porous Ceria Synthesized by Maple Leaf Templates and Its Catalytic Performance

Hierarchical porous ceria with nanocrystalline was successfully synthesized using maple leaf as a bio-template. Unique biomorphic microstructures were characterized by Field Emission Scanning Electron Microscope (FESEM), transmission electron microscope (TEM) and nitrogen absorption-desorption technique. The obtained ceria material shows the repetitious biomimetic structure consisting of the stoma porous about several mu m and nanopores with 2-4 nm apertures. The small crystal grain (6-8 nm) and the high specific surface area (64.4 m(2)/g) of porous CeO2 are detected by wide-angle X-ray diffraction (XRD), high resolution TEM (HRTEM) and the BET method. The catalytic property is evaluated by the oxygen storage/release capacity (OSC). The test confirms that hierarchical porous material possesses more surface active oxygen than nonporous ceria does. While the concentration of acid fuchsine is 40 mg/L, the porous sample has a higher decoloring rate in a shorter time than others. The decoloring rate can reach 100% after decolored for 300 min. The investigation infers that the hierarchical porous ceria exhibits better catalytic activity and higher adsorptive capacity in dye wastewater purification due to smaller crystallite size, higher surface area and enhanced OSC.