Hydrothermal synthesis and photocatalytic activity of zinc oxide hollow spheres
Hydrothermal synthesis and photocatalytic activity of zinc oxide hollow spheres
复制标题
氧化锌空心球的水热合成及其光催化活性
DOI：
10.1021/es800036n
复制
发表时间：
2008-07-01
影响因子：
11.4
通讯作者：
Yu, Xiaoxiao
中科院分区：
文献类型：
--
作者：
Yu, Jiaguo;Yu, Xiaoxiao
采用180℃水热法制备具有多孔壳的ZnO空心球，在不同温度下煅烧4 h。采用x射线衍射、扫描电镜、透射电镜和氮吸附-脱附等温线对制备的样品进行了表征。在常温下对罗丹明B水溶液进行光催化脱色，考察了所制备样品的光催化活性。结果表明，通过改变葡萄糖与锌离子的摩尔比(R)，可以控制ZnO空心球的平均晶粒尺寸、壳厚、比表面积、孔结构和光催化活性。随着R的增大，光催化活性增大，并在R = 15时达到最大值，这是比表面积、多孔结构和晶粒尺寸等多种因素共同作用的结果。进一步的结果表明，与传统的粉末光催化剂相比，空心球在光催化反应后更容易通过过滤或沉淀从浆料体系中分离出来并重复使用。经过多次循环光降解RhB，催化剂的活性没有大的损失，证实了ZnO空心球是稳定的，没有光腐蚀。制备的氧化锌空心球在太阳能电池、催化、分离技术、生物医学工程和纳米技术等领域也具有重要的应用价值。
ZnO hollow spheres with porous crystalline shells were one-pot fabricated by hydrothermal treatment of glucose/ZnCl2 mixtures at 180 degrees C for 24 h, and then calcined at different temperatures for 4 h. The as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and nitrogen adsorption-desorption isotherms. The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic decolorization of Rhodamine B aqueous solution at ambient temperature. The results indicated that the average crystallite size, shell thickness, specific surface areas, pore structures, and photocatalytic activity of ZnO hollow spheres could be controlled by varying the molar ratio of glucose to zinc ions (R). With increasing R, the photocatalytic activity increases and reaches a maximum value at R = 15, which can be attributed to the combined effects of several factors such as specific surface area, the porous structure and the crystallite size. Further results show that hollow spheres can be more readily separated from the slurry system by filtration or sedimentation after photocatalytic reaction and reused than conventional powder photocatalyst. After many recycles for the photodegradation of RhB, the catalyst does not exhibit any great loss in activity, confirming ZnO hollow spheres is stability and not photocorroded. The prepared ZnO hollow spheres are also of great interest in solar cell, catalysis, separation technology, biomedical engineering, and nanotechnology.