Facile hydrothermal synthesis of single crystalline TiOF2 nanocubes and their phase transitions to TiO2 hollow nanocages as anode materials for lithium-ion battery

Single-crystalline TiOF2 nanocubes with edge length of around 200–300 nm have been synthesized under hydrothermal conditions using titanium (IV) isopropoxide (TIP) as titanium source, HF as etchant. The corresponding hollow TiO2 nanocages with dominantly exposed {0 0 1} crystal planes can be easily obtained by calcinating TiOF2 nanocubes under air atmosphere. It is also found that the presence of acetic acid not only being chemical modifier of TIP to lower its reactivity at relatively acid environment, but also gives rise to a uniform hollow TiO2 nanocages which play the crucial role in hollow formation. The TiOF2 electrode presented here exhibits much excellent electrochemical performance. The initial high specific capacity of TiOF2 can be up to 1045 mAh g−1 at a rate of 30 mA g−1. The specific discharge capacity is 510 mAh g−1 after 40 cycles.

► Using titanium (IV) isopropoxide as titanium source to fabiricate the uniform single crystalline TiOF2 nanocubes with edge length of around 200–300 nm. ► Confirm that acetic acid play a crucial role in TiO2 hollow structure formation. ► Both such nanosized TiOF2 and hollow cubic TiO2 nanocage with dominantly exposed {0 0 1} crystal planes have not yet been synthesized for lithium ion battery application presently, furthermore, exhibit outstanding electrochemical properties.