不同形貌ZnO的制备及其光催化性能研究

Preparation of ZnO with different morphology and their photocatalytic activity

以柠檬酸钠为辅助剂,通过改变其加入量采用水热法制备不同形貌的ZnO。分别运用X射线衍射、扫描电子显微镜、透射电子显微镜和比表面积等手段对样品进行分析,并对生长机理进行了研究。另外,采用氙灯模拟太阳光,来探讨不同形貌ZnO对有机染料亚甲基蓝溶液的降解效果。结果表明:水热法合成的最终产物均为结晶性良好的六方纤锌矿,随着柠檬酸钠量的增加,ZnO的形貌由棒状花型到中空微球再转变为核壳结构微球。当柠檬酸钠用量为0.02g时,得到2~4μm的中空微球ZnO具有较高的催化活性,主要归功于其具有较大的比表面积(22.53m2/g)和特殊的内部空穴结构。

With the assistance of trisodium citrate,the various microstructures of ZnO were synthesized by hydrothermal method using different trisodium citrate concentration.The structure and morphology of as-prepared products were characterized by XRD,SEM,TEM and BET,and the formation mechanism of ZnO microstructure was studied.In addition,the photodegradation of aqueous solution of methylene blue in the presence of different morphological ZnO was studied under 500 W Xe lamp irradiation which used as the simulated solar light.The results indicated that the final production were hexagonal wurtzite structure with good crystallinity,and the morphology of ZnO changed from rod-like to hollow microsphere,and then to core-shell microsphere with the increase of concentration of trisodium citrate.ZnO with hollow-sphered morphology was prepared as the amount of trisodium citrate was 0.02 g,and the diameter of ZnO hollow microsphere was around 2~4μm.It exhibited superior photocatalytic activities compared with ZnO samples.The outstanding photocatalytic activity was mainly due to its unique hollow structure and larger surface area（22.53 m2/g）.