Visible-Light-Driven Photodegradation of Commercial Dyes by the Cooperation of Co-Doped TiO2 Material

The Co-doped TiO₂ photocatalysts with various contents of Co were fabricated by co-precipitation method combined with calcinations at 500°C. Two different dyes of rhodamine b and methylene blue were used to evaluate the photocatalytic performance of the prepared samples. The different concentration of Co has significant influence on structural, morphological, optical properties as well as photocatalytic activity of TiO₂ catalyst. The XRD diffraction patterns of all samples exhibit the anatase phase. X-ray photoelectron spectroscopy technique was used to investigate the chemical state of prepared samples. The BET measurement shows larger specific surface area of doped samples than that of pure TiO₂. The incorporation of Co ions into TiO₂ results in the red-shift in photo-absorption of samples toward visible region. The photocatalytic activities on rhodamine b and methylene blue dyes degradation clearly show that the performance of photodegradation highly depends on the concentration of dopant contents and type of organic dyes. The Co-doped TiO₂ sample with 3% of Co dopant concentration exhibited superior photodegradation rate under visible light illumination in both of rhodamine b and methylene blue dyes. The influences of dopant ions and concentration on physical properties, optical absorption and photocatalytic activity on TiO₂ are also discussed.

Keywords: Co-doped TiO₂; Photocatalyst; co-precipitation method

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                                           E-mail: chakkaphan_w@rmutt.ac.th