A strategy to synthesize hollow micro/nanospheres with tunable shell thickness

A simple one-step direct templating method is developed to synthesize hollow carbon and sandwich-like ZnO/C/ZnO micro/nanospheres. The type and shell thickness of the final products can be controlled by simply adjusting the reaction temperature. The removal of the templates can also be easily controlled during the synthesis. At a low temperature, the templates remain in the products to form hollow sandwich-like micro/nanospheres. As the reaction temperature rises, the templates are consumed, which results in the preparation of hollow carbon micro/nanospheres. On the basis of a series of experiments, we propose a simple plausible mechanism to address the original strategy for synthesizing these hollow micro/nanospheres. Furthermore, the sandwich-like ZnO/C/ZnO nanospheres can be used as the anode in lithium-ion batteries, exhibiting an extraordinary cyclability and a high coulombic efficiency. This approach can be extended to the synthesis of other hollow spheres. Further investigation is underway in our group.