以枫叶为模板合成分级多孔氧化铈材料及其催化性能

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

以枫叶为生物模板合成了由纳米颗粒构成的分级多孔氧化铈材料.采用场发射电子显微镜（FESEM）、透射电子显微镜（TEM）和氮气脱吸附技术表征了材料的独特生物形态微结构,其仿生结构是由复制气孔得到的微米孔和复制细胞孔得到的2~4 nm的小孔构成.通过广角X射线衍射（XRD）、高分辨透射电子显微镜（HRTEM）和BET计算发现多孔氧化铈具有很小的晶粒（6~8 nm）和较大的比表面积（64.4 m2/g）.利用化学储氧量（OSC）评价了样品催化性能,结果表明：分级多孔氧化铈比无孔氧化铈含有更多的表面活性氧.当将材料用于酸性品红脱色反应,由于分级多孔氧化铈材料的颗粒小,比表面积大和化学储氧量高,其在染料废水净化处理时具有较好的催化活性和吸附能力,到300 min时脱色率可达到100%.

Hierarchical porous ceria with nanocrystalline was successfully synthesized using maple leaf as a biotemplate. 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 um and nanopores with 2-4 nm apertures. The small crystal grain （6-8 nm） and the high specific surface area （64.4 mE/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 act}vity and higher adsorptive capacity in dye wastewater purification due to smaller crystallite size, higher surface area and enhanced OSC.