关键词: TiO2纳米管阵列膜, 钴离子(Co2+)掺杂, 可见光, 阳极氧化, 光生阴极保护

Abstract: A highly ordered Co-doped TiO2 nanotube layers were fabricated by potentiostatic anodization of pure titanium in fluorinated electrolyte solutions followed by ion-exchange method. The structure and composition of the as-prepared Co-doped TiO2 nanotube layers were characterized by SEM, XRD, UV-Vis, and XPS. The effects of dopant content on the morphologies, structural and photochemical properties of the TiO2 nanotube arrays were investigated. The performances of photogenerated cathodic protection and the photoelectrochemical response for the Co-doped TiO2 nanotube arrays under illumination and dark conditions were evaluated through the electrochemical measurements. The Co-doped TiO2 nanotubes showed a stronger absorption in the visible light range due to a low recombination of photogenerated hole-electron. The open-circuit potentials of 403 stainless steel coupled with the Co-doped TiO2 nanotube arrays shifted negatively under visible light irradiation. It was indicated that the Co-doped TiO2 nanotube arrays were able to provide an effective photogenerated cathodic protection for metals under regular sunlight conditions.

Key words: anodic oxidation, TiO2 nanotube, Co-doped, photocathodic protection, visible-light