水热法制备纳米TiO2及其等电点的研究

水热法制备纳米TiO2及其等电点的研究

丘永　樑,  陈洪龄,  汪效祖,  徐南平

(南京工业大学化学化工学院,  江苏省材料化学工程重点实验室,  江苏 南京 210009)

摘  要：研究了在200℃，6小时水热过程中不同pH条件对合成纳米二氧化钛粉体等电点的影响。以偏钛酸为原

料，用NaOH和HCl调节酸碱度，在不同pH条件下水热合成了二氧化钛微粒，其平均粒径均在15~40nm。对不

同pH条件下制得的二氧化钛微粒进行了Zeta电位、XRD和TEM表征。微粒晶型为锐钛型。对微粒的等电点进

行分析，不同的pH水热反应条件影响到合成粉体吸附的表面羟基数量，从而影响到微粒的等电点。 在pH

1,3,5,11,13水热条件下制得的微粒等电点为5.5，在pH 7，9水热条件下制得的微粒等电点为4.5 。反应物料在酸

性水热条件下反应后酸性增强，在碱性水热条件下反应后碱性增强。

关键词：偏钛酸；水热合成；等电点；纳米二氧化钛；锐钛型

中图分类号：TQ134.11；O614.411                  文献标识码：A

Preparation of Nanometer Titanium Dioxide Powders by Hydrothermal Method and

their Isoelectric Points

QIU Yong-liang,  CHEN Hong-ling,  WANG Xiao-zu,  XU Nan-ping

(Key Laboratory of Material-Oriented Chemical Engineering of Jiangsu Province, College of Chemistry and

Chemical Engineering, Nanjing University of Technology, Nanjing 210009, China)

Abstract：Through the hydrothermal process at 200℃ for 6h and using the metatitanic acid as reactant, the nanometer titanium dioxide powder were synthesized under different pH values adjusted by NaOH or HCl solution. The synthesized powders were characterized by Zeta potential, XRD and TEM. The TEM photographs show that the crystal structures are all anatase. The influence of pH on the isoelectric points of the synthesized titanium dioxide powders was studied and it shows that the pH conditions could influence the quantity of surface hydroxyl absorbed by the synthesized powders, thus influence the isoelectric points. Isoelectric points of the powders prepared in hydrothermal process with pH 1，3，5，11，13 are 5.5. and those in hydrothermal process with pH 7，9 are 4.5. When the hydrothermal reaction is processed in the acid solution then the acidness of the reactant will be increased, and when the reaction is processed in the alkaline solution, then the increase will be the alkelity of the reactant.

Key words： metatitanic acid;  hydrothermal method;  isoelectric point;  nanometer titanium dioxide;

anatase