A Versatile Kinetics-Controlled Coating Method To Construct Uniform Porous TiO2 Shells for Multifunctional Core-Shell Structures

The development of a simple and reproducible route to prepare uniform core@TiO2 structures is urgent for realizing multifunctional responses and harnessing multiple interfaces for new or enhanced functionalities. Here, we report a versatile kinetics controlled coating method to construct uniform porous TiO2 shells for multifunctional core-shell structures. By simply controlling the kinetics of hydrolysis and condensation of tetrabutyl titanate (TBOT) in ethanol/ammonia mixtures, uniform porous TiO2, shell core-shell structures can be prepared with variable diameter, geometry, and composition as a core (e.g., alpha-Fe2O3 ellipsoids, Fe3O4 spheres, SiO2 spheres, graphene oxide nanosheets, and carbon nanospheres). This method is very simple and reproducible, yet important, which allows an easy control over the thickness of TiO2 shells from 0 to similar to 25, similar to 45, and similar to 70 nm. Moreover, the TiO2 shells possess large mesoporosities and a uniform pore size of similar to 2.5 nm, and can be easily crystallized into anatase phase without changing the uniform core-shell structures.