Photoactivity of an anodized biocompatible TiNbSn alloy prepared in sodium tartrate/hydrogen peroxide aqueous solution

A bioactive TiNbSn alloy was anodized in an electrolyte of sodium tartrate containing hydrogen peroxide (H2O2). The photo-induced characteristics of the anodized alloy were explored by focusing on its crystallinity and electrochemical conditions. The electrolysis curve of the anodization exhibited a higher voltage in the TiNbSn substrate than in the pure Ti substrate. Highly crystallized porous rutile-structured TiO2 was formed on TiNbSn, whereas relatively low-crystallized glassy anatase-structured TiO2 was formed on Ti. The absorption spectra of the oxide, formed on TiNbSn, revealed a steep absorption decrease with increasing wavelength while an explicit transition was not observed for the oxide formed on Ti. The anodized TiNbSn alloy exhibited superior photoactivity and generated hydroxyl radicals under ultraviolet (UV) illumination. The photoactivity of the anodized TiNbSn was attributed to TiO2, which was highly crystallized by the application of a high voltage, thus suppressing the recombination of the photogenerated carriers.