pH值对水热合成氧化锌粉体形貌及光催化性能的影响

发布时间：2018-06-12 08:19

本文选题：氧化锌 + pH值　；参考：《陶瓷学报》2017年05期

【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。
[Abstract]:Zinc oxide nanocrystalline powders were successfully prepared by hydrothermal method using ZnN _ 3H _ 2O as raw material NaOH as mineralizer and citric acid as surfactant under the condition of pH 8.0-12.0. The phase, morphology, energy band gap, specific surface area and stability of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis diffuse reflectance spectroscopy (UV-VRS), low temperature nitrogen adsorption and Fourier transform infrared spectroscopy (FTIR). The photocatalytic degradation of 15 mg / L methyl orange solution was evaluated. The results showed that the photocatalytic degradation of methyl orange was the best when the pH value of the first order reaction was 12 (no citric acid), and the degradation rate of methyl orange reached 99g when irradiated with 300W high pressure mercury lamp for 2 h. In addition, pH value has a great influence on the phase, morphology and photocatalytic performance of ZnO powder, but the specific surface area of the prepared powder is larger, but the degree of crystallization is poor. The ZnO powder with high crystallinity and hexagonal wurtzite structure was synthesized at pH = 12.0 (without citric acid). The specific surface area of ZnO powder was 8.99 mt2 g / L, and the photocatalytic performance was excellent.
【作者单位】：江西科技师范大学江西省材料表面工程重点实验室;
【基金】：国家自然科学基金(51162009) 江西省自然科学基金(20151BAB204009)
【分类号】：TQ132.41

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