Synthesis of Various Generations Titania Nanotube Arrays by Electrochemical Anodization for H2 Production

The synthesis of second, third and fourth generation of highly ordered titania nanotubular photoanodes by electrochemical anodization of Ti thin foils in different electrolytes is reported. Field emission gun scanning electron microscope analysis indicated that films composed by nanotubes have a high porous tubular morphology. X-ray diffraction results confirmed that annealed titania nanotubes have anatase/rutile phase. Diffuse reflectance UV-Vis spectra analysis indicated that the band gap for various generation titania nanotube arrays as 3.0, 2.8 and 2.5 eV. The hydrogen generation of second, third and fourth generation titania nanotube arrays at an illumination of 10 mW/cm2 for 1 h is 0.10, 0.28 and 0.36 mL respectively.