PANI/Bi12TiO20 complex architectures: Controllable synthesis and enhanced visible-light photocatalytic activities

Bi₁₂TiO₂₀ complex architectures (BiT) with flower-, spindle- and jujube-like shapes, were prepared through a facile template-free hydrothermal process, by controlling the reaction parameters, such as temperature, reagent concentration, and reaction time. Within the hydrothermal temperature range from 150 to 200°C, the morphology transformed progressively from microjujube to microflowers consisted with nanospindles. A possible growth mechanism for BiT architectures was proposed to explain the transformation of nanoparticles to microflowers via an Ostwald ripening mechanism followed by self-assembly. Most importantly, much higher photocatalytic activities of BiT spindle-like structures modified with 0.5% polyaniline (PANI) via a simple chemisorption approach in comparison with unmodified BiT were obtained for the degradation of Rhodamine B (RhB) solution under visible-light irradiation (λ>420nm). Furthermore, an enhanced photocatalytic performance for RhB degradation was also observed with the assistance of a small amount of H₂O₂. The reason could be ascribed to the synergic effect between PANI and BiT, which promoted the migration efficiency of photogenerated electron-hole on the interface of PANI and BiT, demonstrating that PANI/BiT architecture is a promising candidate as a visible light photocatalyst.