Preparation and visible-light-driven photoelectrocatalytic properties of boron-doped TiO2 nanotubes

In the present study, chemical vapour deposition (CVD) was applied to dope boron into TiO2 nanotubes anodized Ti in C2H2O4-2H(2)O + NH4F electrolyte with the goal of improving the photocatalytic (PC) activity under visible light. The undoped TiO2 nanotubes had a highly self-organized structure. However, after doping through CVD, TiO2 nanotubes suffered from an observable disintegration of morphological integrity. X-ray diffraction (XRD) results confirmed that annealing temperature had an influence on the phase structure and boron impurities could retard anatase-rutile phase transition. Diffuse reflectance absorption spectra (DRS) analysis indicated that B-doped samples displayed stronger absorption in both UV and visible range. B-doped TiO2 nanotubes electrode annealed at 700 degrees C through CVD showed higher photoelectrocatalytic (PEC) efficiency in methyl orange (MO) degradation than that annealed at 400 degrees C and 550 degrees C. MO degradation was substantially enhanced with the increasing applied bias potential. Moreover, there was a synergetic effect between the electrochemical and photocatalytic processes, and the synergetic factor R reached 1.45. B-doped TiO2 nanotubes electrode showed good stability after 10 times by repeating photoelectrocatalysis of MO. (C) 2008 Elsevier B.V. All rights reserved.