Investigation on the Photoelectrocatalytic Activity of Well-Aligned TiO2Nanotube Arrays

Well-aligned TiO 2 nanotube arrays were fabricated by anodizing Ti foil in viscous F − containing organic electrolytes, and the crystal structure and morphology of the TiO 2 nanotube array were characterized and analyzed by XRD, SEM, and TEM, respectively. The photocatalytic activity of the TiO 2 nanotube arrays was evaluated in the photocatalytic (PC) and photoelectrocatalytic (PEC) degradation of methylene blue (MB) dye in different supporting solutions. The excellent performance of ca. 97% for color removal was reached after 90 min in the PEC process compared to that of PC process which indicates that a certain external potential bias favors the promotion of the electrode reaction rate on TiO 2 nanotube array when it is under illumination. In addition, it is found that PEC process conducted in supporting solutions with low pH and containing Cl − is also beneficial to accelerate the degradation rate of MB.