分级介孔结构组成的ZnO微球及光催化性能

Preparation and Photocatalytic Property of the Hierarchical Mesoporous ZnO Microspheres

以硝酸锌、脲素及酒石酸为反应物,采用水热法制备碱式碳酸锌前驱体微球,通过煅烧前驱体制备了介孔氧化锌微球。通过扫描电子显微镜（SEM）可以观察到,氧化锌微球的直径约为2~4μm,由大量厚度约为10 nm的介孔纳米片组装而成。X射线衍射（XRD）和透射电镜（TEM）结果表明：ZnO微球为六方纤锌矿结构,结晶较好。比表面积测试（BET）表明ZnO微球为介孔材料,孔径为20~50 nm,ZnO微球比表面积约为29.8 m2/g。以亚甲基蓝为目标降解物,对介孔氧化锌微球进行了光催化降解实验。实验结果表明,所合成的介孔ZnO微球对亚甲基蓝的光催化性能较好。

The zinc hydroxide carbonate （ZHC） precursor was synthesized by hydrotherrnal method in a autoclave using zinc nitrate hexahydrate, urea and tartaric acid as the source materials. Hierarchical porous ZnO microspheres have been successfully synthesized by calcining the microspheric ZHC. The result of scanning electron microscope （SEM） shows that the as-prepared ZnO microspheres with a diameter between 2-4 μm. The microspheres are assem- bled by numerous porous nanosheets which have the uniform thickness about 10 nm. The hierarchical ZnO microspheres were further charactered by X-ray diffraction （XRD） and transmission electron microscope （TEM）, the results clearly show that the ZnO microspheres exhibit a typical wurtzite structure and are well crystallized. Brun- auer-Emmett-Teller（BET） confirms that the ZnO microspheres are hierarchical mesoporous structures, the diameter of mesoporous on the nanosheets are in the range of 20-50 nm. The specific surface area of the ZnO microshperes is about 29.8 m2/g. The photocatalytic activity of the ZnO microspheres was evaluated by photode-gradation reaction of methylene blue （MB）. The results show that the hierarchical porous ZnO microspheres exhibit high photocatalytic activity.