Constructing Hierarchical Spheres from Large Ultrathin Anatase TiO2 Nanosheets with Nearly 100 Exposed (001) Facets for Fast Reversible Lithium Storage

摘要

Synthesis of nanocrystals with exposed high-energy facets is a well-knownchallenge in many fields of science and technology. The higher reactivity of these facetssimultaneously makes them desirable catalysts for sluggish chemical reactions and leadsto their small populations in an equilibrated crystal. Using anatase TiO2 as an example,we demonstrate a facile approach for creating high surface area, stable nanosheetscomprised of nearly 100% exposed (001) facets. Our approach relies on spontaneousassembly of the nanosheets into three-dimensional, hierarchical spheres that stabilizesthem from collapse. We show that the high surface density of exposed TiO2 (001) facetsleads to fast lithium insertion/deinsertion processes in batteries that mimic features seenin high power electrochemical capacitors.