A novel hydrolytic reaction to morphology-controlled TiO2 micro/nanostructures for enhanced photocatalytic performancesElectronic supplementary information (ESI) available. See DOI: 10.1039/c5ra04524j

Different TiO 2 micro/nanostructures have been hydrothermally prepared through controlling the hydrolysis and nucleation rate of Ti 4+ ions by urea and H 2 O 2 in a (NH 4 ) 2 TiF 6 aqueous solution. Anatase TiO 2 nanorods with diameters of 10-30 nm and lengths up to 300-500 nm were evolved from the intermediate monoclinic H 2 Ti 5 O 11 ·3H 2 O in the presence of H 2 O 2 and urea, whereas TiO 2 core-shell nanospheres with diameters of 300-500 nm were obtained with the sole assistance of urea via the Ostwald ripening effect and TiO 2 microspheres with diameters of about 1-2 μm were formed in the presence of only H 2 O 2 . Photocatalytic degradation of Rhodamine B (RhB) has been used to evaluate their activities. The results indicate that the anatase TiO 2 nanorods have superior photocatalytic efficiency to the core-shell nanospheres and microspheres counterparts owing to their larger specific surface area and higher yield of &z.rad;OH radicals. This work not only offers a simple and promising route to the controllable synthesis of various TiO 2 architectures, but also provides new insight for improving the photocatalytic performance of TiO 2 through morphological engineering, which will have potential applications in environmental remediation. TiO 2 nanorods, core-shell nanospheres, and microspheres were prepared via tuning the hydrolysis and nucleation rate of Ti 4+ ions. Superior photocatalytic efficiency of TiO 2 nanorods attributes to large surface area and high ⋅OH radical productivity.