Citation: LI Zhen, LIU Han-Meng, YAO Zhi-Xia, SUN Yu-Jing, LI Zhuang. Preparation and Characterization of Titanium Dioxide Nanotube Array/Titanium pH Electrode. Chinese Journal of Analytical Chemistry, 2018, 46(12): 1961-1967. doi: 10.11895/j.issn.0253-3820.181459 [复制]
Preparation and Characterization of Titanium Dioxide Nanotube Array/Titanium pH Electrode
采用阳极氧化法，在含有NH4F以及乙二醇和水的混合溶液中，阳极氧化金属钛丝，制备二氧化钛纳米管阵列/钛(TiO2 NTAs/Ti)作为pH电极。利用扫描电镜(SEM)、X射线衍射(XRD)和X射线光电子能谱(XPS)对电极进行了表征。考察了电极的亲水性以及表面化学吸附氧OH)(性能，探究了pH响应机理。当控制电解电压为30 V、电解液为含有NH4F (0.5%，w/w)以及乙二醇和水(9:1，V/V)的混合溶液、阳极氧化时间为10 min时，制备的TiO2 NTAs/Ti电极在B-R缓冲溶液(pH=3~11)中具有最佳pH响应，灵敏度为(-55.17 ±0.28) mV/pH，相关系数(R2)>0.9966。常见离子对电极的影响可以忽略不计。制备的pH电极具有良好的稳定性，并成功用于维生素饮料和海水pH值的测定。
A method for rapidly preparing titanium dioxide nanotube array/titanium (TiO2 NTAs/Ti) as a pH electrode by using anodization method in a mixed solution containing NH4F and ethylene glycol and water was established. The electrodes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The possible pH response mechanisms were discussed by the hydrophilicity, specific surface area, and surface chemisorbed oxygen (OH) of the electrodes. Under the optimized conditions including electrolysis voltage of 30 V, a mixed solution containing NH4F (0.5%, w/w) and ethylene glycol and water (9:1, V/V) as electrolyte and anodization time of 10 min, the prepared TiO2 NTAs/Ti electrode in Beretan-Robson (B-R) buffer solution (pH=3-11) exhibited an excellent pH response with a sensitivity of (-55.17±0.28) mV/pH and a correlation coefficient (R2) of above 0.9966. The results of the ion interference experiments showed that the effect of common ion on the electrode was negligible. The electrode had good stability and was successfully applied to the determination of pH value of vitamin drink and seawater.