TiO2/polyaniline composites: An efficient photocatalyst for the degradation of methylene blue under natural light

Polyaniline (PAn) sensitized nanocrystalline TiO2 composites (TiO2/PAn) were successfully prepared and used as an efficient photocatalyst for the degradation of dye methylene blue (MB). The results showed that PAn was able to sensitize TiO2 efficiently and the composite photocatalyst could be activated by absorbing both the ultraviolet and visible light (λ: 190 ∼ 800 nm), whereas pure TiO2 absorbed ultraviolet light only (λ < 380 nm). Under the irradiation of natural light, MB could be degraded more efficiently on the TiO2/PAn composites than on the TiO2. Furthermore, it could be easily separated from the solution by simple sedimentation.