Facile Synthesis of Hollow TiO2 Single Nanocrystals with Improved Photocatalytic and Photoelectrochemical Activities

Diverse titanium dioxide (TiO2) nanostructures have attracted considerable attention owing to their broad applications in photocatalytic and photoelectrochemical fields. Herein, TiO2 hollow single nanocrystals are reported for the first time by using TiO2 nanopowders as the raw material and hydrofluoric acid as a capping and etching agent through a simple hydrothermal treatment. The influence of experimental parameters such as the concentration of HF, the amount of TiO2 nanoparticles, the reaction time, and temperature was investigated systematically. The obtained hollow single nanocrystals exhibited enhanced photoelectrochemical and photocatalytic performances attributed to their good crystallinity, suppressed charge recombination, and increased active sites. The current study will provide new insights into the nanostructured engineering of anatase TiO2 as well as opportunities for the controllable synthesis of hollow single nanocrystals.