Sonoelectrochemical synthesis of low band gap titania nanotubes for photoelectrochemical generation of hydrogen

摘要

The sonoelectrochemical method is a highly efficient technique for the synthesis of well ordered and robust titanium dioxide nanotube arrays. Self ordered arrays of TiO2 nanotubes of various diameters and length can be rapidly synthesized under an applied potential of 5-20 V in the presence of organic electrolyte solvents like ethylene glycol. The TiO2 nanotubes prepared in the organic electrolytes and annealed under N2 atmospheres give a TiO2-xCx type of semiconductor materials having a band gap of 2.0 eV. The hybride nanotubes demonstrated promising efficiency in splitting water in the presence of solar light. In addition, the modeling of titania nanotubes using the first principles of the Density Functional Theory (DFT) approach is underway for calculating electronic properties of the TiO2 nanotubular structure. It is envisioned that the DFT modeling will yield valuable information in developing improved titania photoanodes for high efficiency photoelectrochemical splitting of water.