TiO_2纳米管阵列的制备及其光催化产氢活性研究

Preparation of TiO_2 Nanotube Arrays for Photocatalytic Hydrogen Generation

采用阳极氧化法在乙二醇电解液中制备了高度有序的TiO2纳米管阵列,分别通过SEM、EDX表征其形貌及元素组成,并探讨了TiO2纳米管的生长过程。结果表明,TiO2纳米管的形成过程是一个由纳米多孔膜结构向独立有序的纳米管阵列转变的过程。同时以TiO2纳米管为光阳极,采用双室光电化学池制氢体系,利用光照TiO2产生的光电压与双室电解液pH差产生的化学偏压的协同效应可达到水的分解电压,充分实现高效率、低能耗制氢的目标。无外加电压及牺牲剂条件下,TiO2纳米管的光电流密度为6.51 m A/cm2,光照1 h产氢量高达108.9μmol/cm2。

Highly-ordered TiO2 nanotube arrays were synthesized by anodic oxidation of titanium foil in ethylene glycol electrolyte.The morphology and element composition of the TiO2 nanotubes were characterized by SEM and EDX,respectively.The growth process of the TiO2 nanotubes was also discussed.The results indicate that the formation of TiO2 nanotubes is a transformation process from nanoporous structure to individual nanotube arrays structure.Moreover,efficient hydrogen production with low energy consumption is achieved using TiO2 nanotubes as photoanode in the two-compartment photoelectrochemical（PEC） cell,in which the photovoltage of TiO2 cooperates with a chemical bias produced by the pH difference between acidic electrolyte and alkaline electrolyte to reach the voltage of water splitting.Without any external applied voltage or sacrificial agent,the photocurrent density TiO2 nanotubes is 6.51 mA/cm^2 and the hydrogen production rate of 108.9 μmol/cm2 is obtained under solar light illumination for 1 h.