Biomineralized Mesocrystal KCl Microreactor for Solid-State Synthesis of Non-Oxide Nanomaterials

Inspired by natural biomineralization, a biomineralized microreactor with a mesocrystal KCl shell (BM-KCl-MMs) is made by a facile freezing dry process, exhibiting a good availability for high-temperature solid-state synthesis of nanomaterials. Benefiting from the good thermal stability, stiffness, and mechanical strength of KCl mesocrystal shells, the employment of BM-KCl-MMs in the transition metal (TM)-S-Se system not only realizes for the first time, the production of TMS_x Se_{2- x} /C nanocomposites in air atmosphere, but also reaches a high reagent-utilization and high yield, as well as minimum wastes. More importantly, based on the soaking effect of the KCl shells, the resultant stable reaction microenvironment inside endows the microreactors with a well-controlled synthesis of nanomaterials with very even size, uniform dispersion, and novel functionalities. As one example, the as-prepared MoS_x Se_{2- x} /C composites as the electrodes of K-ion batteries and K-ion hybrid supercapacitors deliver the state of the art cycling capability of 248 mAh g^-1 at 2 A g^-1 after 5000 cycles and an 87.1% capacity retention at 5.0 A g^-1 after 20 000 cycles, respectively, demonstrating a significant potential of BM-KCl-MMs on design and synthesis of novel functional nanomaterials.