反萃沉淀法制备纳米氧化锌及其光催化动力学  

Preparation and Photocatalytic Kinetics of Nano-ZnO Powders by Precipitation Stripping Method

作　　者：徐航[1] 张东翔[2] 徐文国[1] 

机构地区：[1]北京理工大学理学院,北京100081 [2]北京理工大学化工与环境学院,北京100081

出　　处：《北京理工大学学报》2007年第7期641-645,共5页Transactions of Beijing Institute of Technology

基　　金：国家自然科学基金资助项目(20476010)

摘　　要：以二(2-乙基己基)磷酸(HDEHP)为萃取剂,CCl4为稀释剂,H2C2O4—CH3CH2OH—H2O溶液为反萃沉淀剂,采用反萃沉淀法制备前躯体二水合草酸锌,经450℃煅烧制备了纳米级氧化锌粉体,用TEM,SEM,TG,XRD和FT-IR等测试手段对材料进行表征.结果表明:部分氧化锌为六角形的多微孔材料,平均粒径约为32 nm.基于Langmuir模型和Photo-Layer模型对氧化锌降解亚甲基蓝的动力学行为进行研究.结果表明:光催化氧化过程的控制步骤为化学反应动力学控制机制,反应动力学符合拟一级动力学;利用Photo-Layer模型可估算出不同反应条件下光反应层中的.OH浓度.Ultra-fine zinc oxalate powders were prepared through precipitation stripping method with Bis（2-ethylhexyl） phosphate （HDEHP） diluted by tetrachloride carbon as an extractant, and oxalic acid ethanol aqueous solution as a re-extractant and precipitator. Zinc oxide powders were obtained by decomposing zinc oxalate powders at 450℃ . The prepared zinc oxide powders were characterized by TEM, SEM, TG, XRD and FT-IR.The photocatalytic performance of methylene blue by zinc oxide was studied based on the Langmuir model and photo-layer model. The results showed that some zinc oxide powders were micro-multipore materials with hexagonal crystal and the particle size was around 32 nm. The photocatalytic process was the control step in chemical reaction. The photo catalytic process followed the pseudo-first order kinetics and · OH concentration inside the photo-layer in different reaction condition were calculated according to the photo-layer model.

关 键 词：反萃沉淀法 氧化锌 光催化 动力学 

分 类 号：O643[理学—物理化学] X7[理学—化学]