Morphology-Controlled Synthesis of SnO2 Nanotubes by Using 1D Silica Mesostructures as Sacrificial Templates and Their Applications in Lithium-Ion Batteries

SnO2 nanotubes with controllable morphologies are successfully synthesized by using a variety of one-dimensional (1D) silica mesostructures as effective sacrificial templates. Firstly, 1D silica mesostructures with different morphologies, such as chiral nanorods, nonchiral nanofibers, and helical nanotubes, are readily synthesized in aqueous solution by using the triblock copolymer Pluronic F127 and the cationic surfactant cetyltrimethylammonium bromide as binary templates. Subsequently, the obtained 1D silica mesostructures are used as sacrificial templates to synthesize SnO2 nanotubes with preserved morphologies via a simple hydrothermal route, resulting in the formation of well-defined SnO2 nanotubes with different lengths and unique helical SnO2 nanotubes with a wealth of conformations. It is revealed that both of the short and long SnO2 nanotubes showed much better performance as anode materials in lithium-ion batteries than normal SnO2 nanopowders, which might be related to the hollow structure of the nanotubes that could alleviate the volume changes and mechanical stress during charging/discharging cycling. Moreover, the capacity and cycling performance of short nanotubes, which showed a specific discharge capacity of 468 mAh g(-1) after 30 cycles, are considerably better than those of long nanotubes because of the more robust structure of the short nanotubes.