阳极氧化法制备TiO2纳米管及其光催化性能

Preparation of TiO_2 Nanotubes by Anodization and Its Photocatalytic Properties

纳米TiO2对诸多环境污染物有显著的光催化降解作用,光催化已发展成为新型环境污染治理技术。本文采用阳极氧化法制备出TiO2纳米管,对比了四种电解液组成（A氟化铵＋硫酸铵＋水;B氟化铵＋硫酸铵＋乙酸＋水;C氟化铵＋硫酸铵＋甘油＋水;D氢氟酸＋二甲基亚砜（DMOS）＋乙醇）对催化剂表面形貌及光催化性能的影响。结果表明,电解液A和C都制备出了形貌清晰的TiO2纳米管,管径约为60～74 nm。样品经400℃煅烧,TiO2晶型主要为锐钛矿相;经500℃煅烧,出现少量金红石相;经700℃煅烧,晶型全部为金红石相。具有良好形貌的TiO2纳米管同时具有良好的紫外光吸收能力。当亚甲基蓝初始浓度为10 mg·L^-1,经500℃煅烧的TiO2纳米管光催化活性最佳,光照30 min亚甲基蓝的降解率达89.98%。亚甲基蓝光催化降解反应符合一级反应动力学,反应速率常数为0.079 30。

Nanosized TiO2 was extensively studied due to its excellent photocatalytic activity. In this work, TiO2 nanotubes were prepared by anodizing Ti in four electrolyte, ammonium fluoride ＋ammonium sulfate ＋water （electrolyte A）; ammonium fluoride＋ammonium sulfate＋acetic acid＋water （electrolyte B）; ammonium fluoride＋ ammonium sulfate＋glycerin＋water （electrolyte C）; Hydrofluoric acid＋Dmethyl sulfoxide＋ethanol （electrolyte D）. The influence of electrolyte composition on the morphology and phocatalytic performance of TiO2 samples was investigated. The results indicated that TiO2 nanotubes could be successfully fabricated using electrolyte A and C, and the tube diameter was in the range of 60-74 nm. When annealed under 400 ℃, anatase phase was dominant; while annealed under 500 ℃, a mixture of rutile and anatase phase appeared; and after annealed at 700 ℃, rutile phase was predominant. TiO2 nanotubes with excellent morphology possess a high UV absorbance. When the initial concentration of methylene blue （MB） was 10 mg·L^-1, the removal of MB reached 89.98% by TiO2 nanotubes annealed at 500 ℃ Pseudo-first-order kinetics was also confirmed in the photocatalytic process of MB, and the apparent rate constant was 0.079 30.