Precisely tailored morphology of polyimine for simple synthesis of metal sulfide/carbon flower-like superstructures

Abstract

Metal sulfide/carbon superstructures are a new class of functional materials for various energy applications due to their strong synergistic effect and favorable geometry. However, developing a controllable way to synthesize metal sulfide/Carbon superstructures with high N doping, well-designed 3D superstructure and refined metal sulfide nanoparticles remains a big challenge. Herein, we report a one-pot synthesis of metal sulfide/carbon flower-like superstructures (MxSy/CFSs) by using metal ion doped polyimine. The morphology of polyimine can be easily tuned by choosing different solvents or different amino monomers. The presence of imine bond and thiophene in polyimine not only can coordinates with metal ion and transforms them into metal sulfide during carbonization, but also provides high N and S doping for the MxSy/CFSs. Benefiting from the advantages of these structures, multiple MxSy/CFSs (such as FeS/CFSs, Co9S8/CFSs, Ni3S2/CFSs, and MnS/CFSs) with high N doping, uniform metal sulfide nanoparticles and hierarchical superstructures were fabricated by directly carbonizing metal ion doped polyimine flower-like superstructures in nitrogen atmosphere. The as-prepared Co9S8/CFSs exhibits superior sodium storage properties with stable cycling performance and excellent rate capacity. This new finding provides a novel strategy to controllably design and produce metal sulfide/carbon flower-like superstructures for the applications in energy storage.