Microscale Hierarchical Three-Dimensional Flowerlike TiO2/PANI Composite: Synthesis, Characterization, and Its Remarkable Photocatalytic Activity on Organic Dyes under UV-Light and Sunlight Irradiation

A microscale hierarchical 3D flowerlike TiO2/PANI composite with enhanced photocatalytic activity was synthesized via a sol-gel method, and the as-synthesized samples were characterized by XRD, SEM, TEM, FT-IR, UV-vis adsorption, BJH, and TGA/DSC. The outcome of the photocatalytic experimental demonstrating the TiO2/PANI hybrid with a Ti/ANI (aniline) molar ratio of 1:1 (denoted as T/P) showed high photocatalytic activity upon the degradation of Congo red (CR) and methyl orange (MO) under both UV-light and sunlight irradiation. The unique hierarchical 3D flowerlike structure endows the T/P hybrid with a large surface area of 38.81 m(2)/g. The intermeshed PANI nanoflakes could make full use of the light resource by multiple reflections between the nanoflakes. Moreover, the intrinsic cavity of the hollow TiO2 nanoparticles can also increase the light-capturing efficiency. The synergistic effect between PANI and TiO2 hollow nanoparticles results in a reduction of the photoinduced electron-hole recombination rate as well as enhanced photocatalytic activity under UV-light and sunlight. Given the unique spatial structure and high photocatalytic characteristics of the T/P composite, there is great potential for applications in water treatment.