Facile synthesis of TiO₂ hierarchical tubes with enhanced photocatalytic activity

Graphical abstract: Hierarchical micro/nanostructured tubular TiO₂ were prepared by impregnation-calcination method with FCT (the fluff of the chinar tree) as biological template and titanium tetrachloride as precursor. The resultant TiO₂ samples possess curly tubular structure and the exterior outline of the samples look like fried dough twist. Moreover, the wall of the tube is assembled with spherical-likely nanoparticles. During the bio-inspired synthetic process, the FCT plays important roles as template and inducer for assembling the tubular micro/nanostructure. Furthermore, the resultant TiO₂ exhibits favorable photocatalytic activity and good stability for degrading methyl orange under UV light irradiation. - Highlights: • The fluff of chinar tree was employed as template and inducer for preparing hierarchical micro/nanostructured tubular TiO₂. • The wall of the micro/nanostructured tubular TiO₂ is assembled with spherical-likely nanoparticles. • The resultant TiO₂ exhibits favorable photocatalytic activity and good recyclability. - Abstract: Hierarchical micro/nanostructured tubular TiO₂ were prepared by impregnation-calcination method with FCT (the fluff of the chinar tree) as biological template and titanium tetrachloride as precursor. The resultant samples possess curly tubular structure and the exterior outline of the samples look like fried dough twist. Moreover, the wall of the tube is assembled with spherical-likely nanoparticles. Apparently in the process of preparation, the FCT played pivotal roles as substrate and inducer for assembling the curly tubular structure of micro/nanostructured TiO₂. Furthermore, the micro/nanostructured TiO₂ have abundant pore structures and large surface area, which are beneficial to the improvement of photocatalytic activity. Under UV light irradiation, the as-prepared TiO₂ exhibits nearly 100% photocatalytic decolorization rate in 30 min and 90% TOC (total organic carbon) degradation rate in 60 min for dye methyl orange (MO).