Abstract
In the present work, highly ordered titanium dioxide (TiO2) nanotube anodes were grown using a rapid anodization process. The photoelectrochemical performances of these electrodes strongly depend on the anodization conditions. Parameters such as electrolyte composition, anodization potential and anodization time are shown to affect the geometrical parameters of TiO2 nanotubes. The optimal anodization parameters are determined by photocurrent measurements, linear sweep voltammetry and electrochemical impedance spectroscopy. The thickness of the tube wall and its homogeneity is shown to strongly depend on the anodization potential, and the formation mechanism is discussed. This study permits the optimization of the photocurrent density and contributes to further improvement of the photoelectrochemical water-splitting performance of TiO2 nanotube photoelectrodes.
Highlights
Since the revolutionary report by Fujishima and Honda in 1972 [1] on water splitting into oxygen and hydrogen using a TiO2 electrode, rigorous research has been devoted to hydrogen production through solar water-splitting processes
Previous works have discussed the formation mechanisms of TiO2 nanotubes based on the field-assisted dissolution theory (FAD) [32], which suggests that the reaction happening at the anode is the oxidation of the titanium metal, releasing Ti4+ and electrons (Equation (1))
It is shown that the length, pore opening and wall thickness critically affect the photoelectrochemical activity of the TiO2 nanotubes
Summary
Since the revolutionary report by Fujishima and Honda in 1972 [1] on water splitting into oxygen and hydrogen using a TiO2 electrode, rigorous research has been devoted to hydrogen production through solar water-splitting processes. The hydrothermal synthesis technique consists of the hydrothermal treatment of titanium dioxide solutions followed by post-annealing treatment, and results in the non-ordered distribution of the TiO2 nanotubes [23]. Among these methods, the electrochemical anodization route is widely investigated, and has attracted great interest since the growth of the very first highly ordered titanium dioxide by Zwilling et al in 1999 [24,25]. The functional properties of TiO2 nanotubes are related to different parameters, such as the crystal structure and surface morphology, which are dependent on the preparation parameters. The effects of the varying anodization parameters on the TiO2 nanotube’s geometrical parameters, as well as their photoelectrochemical properties, were investigated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
