TY - JOUR T1 - Electrochemical Fabrication of Strontium-Doped TiO(2) Nanotube Array Electrodes and Investigation of Their Photoelectrochemical Properties JF - Journal of Physical Chemistry C Y1 - 2011 A1 - Hamedani, H. A. A1 - Allam, N. K. A1 - Garmestani, H. A1 - El-Sayed, Mostafa A AB - In recent years, considerable efforts have been made to improve the performance of photoactive nanostructured materials for water-splitting applications. Herein, we report on the fabrication and photoelectrochemical properties of highly ordered Sr-doped TiO(2) nanotube arrays synthesized via a one-step electrochemical anodization technique. Nanotube arrays of Sr-doped TiO(2) were synthesized via anodization of titanium foil in aqueous electrolytes containing NH(4)F and various concentrations of Sr(OH)(2) at different electrolyte pHs. The morphology and quality of the fabricated materials were found to be significantly affected by the pH of the electrolyte as well as the solubility limit of Sr(OH)(2) in the test electrolyte. The photoelectrochemical measurements revealed that Sr doping can significantly improve the photoconversion efficiency of the material. Using Sr-doped TiO(2) nanotube arrays, an electrode photoconversion efficiency of 0.69% was obtained, which is more than 3 times higher than that of the undoped nanotube arrays (0.2%) fabricated and tested under the same conditions. VL - 115 SN - 1932-7447 N1 - Hamedani, Hoda A. Allam, Nageh K. Garmestani, Hamid El-Sayed, Mostafa A. M3 - 10.1021/jp201194b ER - TY - JOUR T1 - Self-Standing Crystalline TiO(2) Nanotubes/CNTs Heterojunction Membrane: Synthesis and Characterization JF - Acs Applied Materials & Interfaces Y1 - 2011 A1 - Hesabi, Z. R. A1 - Allam, N. K. A1 - Dahmen, K. A1 - Garmestani, H. A1 - El-Sayed, Mostafa A AB - In the present study, we report for the first time synthesis of TiO(2) nanotubes/CNTs heterojunction membrane. Chemical vapor deposition (CVD) of CNTs at 650 degrees C in a mixture of H(2)/He atmosphere led to in situ detachment of the anodically fabricated TiO(2) nanotube layers from the Ti substrate underneath. Morphological and structural evolution of TiO(2) nanotubes after CNTs deposition were investigated by field- emission scanning electron microscopy (FESEM), glancing angle X-ray diffraction (GAXRD), and X-ray photoelectron spectroscopy (XPS) analyses. VL - 3 SN - 1944-8244 N1 - Hesabi, Zohreh R. Allam, Nageh K. Dahmen, Klaus Garmestani, Hamid El-Sayed, Mostafa A. M3 - 10.1021/am200124p ER -