Rational synthesis of highly uniform hollow core–shell Mn3O4/CuO@TiO2 submicroboxes for enhanced lithium storage performance

Abstract

Highly uniform Mn3O4/CuO@TiO2 submicroboxes with hollow and core–shell structure have been synthesized for the first time by a facile and feasible multi-step method. A detail formation mechanism has been proposed based on the chemical and structural characterization, which consists of the part self sacrificing, in situ growth, etching, in situ hydrolysis coating and heat treatment process. The unique firm hollow core–shell structure of Mn3O4/CuO@TiO2 made itself exhibit an enhanced lithium storage performance compared to the hollow Mn3O4/CuO. The TiO2 coatings not only reinforce the hollow structure but also improve the conductivity, which result in the improved electrochemical performance. Typically, a specific capacity of 583mAhg−1 (92.8% of the theoretical capacity of 628mAhg−1) and 97.1% capacity retention (compared with the 2nd discharge capacity) after 150 cycles at 0.2Ag−1 were obtained from the hollow core–shell Mn3O4/CuO@TiO2. This work not only provides a promising strategy to solve the rapid capacity fading and large structure damage of metal oxides but also makes a contribution to the design and synthesis of metal oxides with hollow or core–shell structures for various structure-based applications, such as gas sensors, catalysis and energy storage.