pH值对水热合成氧化锌粉体形貌及光催化性能的影响  

Effect of pH Value on Synthesis of ZnO Powders by Hydrothermal Method and its Photocatalytic Properties

作　　者：周涛[1] 艾建平[1] 陈智琴[1] 汪细平[1] 周泽华[1] 张奎 姜佳丽[1] 李文魁[1] 

机构地区：[1]江西科技师范大学,江西省材料表面工程重点实验室,江西南昌330038

出　　处：《陶瓷学报》2017年第5期655-659,共5页Journal of Ceramics

基　　金：国家自然科学基金(51162009);江西省自然科学基金(20151BAB204009)

摘　　要：以Zn(NO_3)_2·6H_2O为原料,Na OH为矿化剂,柠檬酸为表面活性剂,在pH值为8.0-12.0的条件下采用水热法成功制备出氧化锌纳米粉体。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、紫外-可见漫反射光谱(DRS)、低温氮吸附、傅里叶红外光谱(FT-IR)等手段对样品物相、形貌、能带间隙、比表面积和稳定性进行表征。以样品对15 mg/L的甲基橙溶液的光催化降解性能为评价指标。结果表明,样品对甲基橙的光催化降解反应为表观一级反应,pH值为12(无柠檬酸)时,样品的光催化性能最佳,在300 W高压汞灯照射2 h时甲基橙降解率达到99%。另外,pH值对ZnO粉体的物相、形貌及光催化性能均有较大影响,p H=8.0时合成的粉体比表面积较大,但结晶程度差,劣化其光催化性能;pH=12.0(无柠檬酸)时合成高结晶度的六方纤锌矿结构的ZnO粉体,比表面积为8.99 m^2·g^(-1),光催化性能优异。Zinc oxide nano-powder was prepared by hydrothermal method using zinc nitrate hexahydrate, sodium hydroxide and citric acid by altering the pH of the suspension. The phase, morphology, band gap, specific surface area and stability of ZnO nanorods were studied by X ray diffraction（XRD）, scanning electron microscopy（SEM） and UV-Vis diffuse reflectance spectroscopy（DRS）, low-temperature nitrogen absorption and fourier transform infrared spectrometer（FT-IR）.The photocatalytic properties of different ZnO samples were studied using an ultraviolet lamp as illumination device and 15 mg/L methyl-orange as stimulant pollutant. The results indicate that, the photocatalytic degradation reaction of methyl orange is first order reaction, when the pH=12（No citric acid）, excellent photocatalytic activity of the ZnO powders（2 h, degradation rate reach 99%） under 300 W high pressure mercury lamp. In addition, the pH value has a great influence on the phase, morphology and photocatalytic properties of ZnO powders. Although the specific surface area of the as-prepared powders was largest in pH about 8, the poor degree of crystallinity worsen its photocatalytic properties. ZnO powder was synthesized at pH=12.0（No citric acid） with a high degree of crystallinity and larger specific surface area（about 8.99 m^2·g^（-1））.

关 键 词：氧化锌 PH值 水热合成 光催化 

分 类 号：TQ174.75[化学工程—陶瓷工业]