Building self-ordered tubular macro- and mesoporous nitridated titania from gas bubbles towards high-performance lithium-ion batteries.

Robust well-defined tubular structural materials based on macro- and mesoporous nitridated titania (TMMN-TiO2) were obtained by a simple solution-phase approach in ammonia solution. In this approach, the gas bubbles derived from ammonia solution play the role of templates that direct the ordered growth in the form of a tubular structure. The results demonstrated that the volume ratio of ammonia to water can be favorable for the formation of TMMN-TiO2, which are characterized by FESEM and FTIR. What is more, ammonia was used not only as the template but also as the nitrogen source. Interestingly, it was found that the TiO2 nanocrystals building blocks were assembled into an interconnected mesoporous skeleton and built in ordered tubular macroporous channels. This unique architecture provides many important features that are required for high-performance anodes, such as fast ion transport, high conductivity, and structure stability, thus enabling an electrode with outstanding lithium storage performance. For example, such an electrode delivers 112 mA h g(-1) capacity at 5100 mA g(-1) (30 C) even after 1200 cycles.