Solvent-free nanocasting toward universal synthesis of ordered mesoporous transition metal sulfide@N-doped carbon composites for electrochemical applications

Transition metal sulfides (TMSs) have a wide range of applications owing to their intriguing properties. Significant efforts have been devoted to nanostructuring TMSs to enhance their properties and performance, still there is a high need in general synthesis of TMS nanostructures. Herein, for the first time, a simple solvent free reactive nanocasting approach that integrates solid precursor loading, in-situ sulfuration and carbonization into a single heating step is developed for the universal synthesis of ordered mesoporous TMS@N-doped carbon composites (denoted as OM-TMS@NCs) with methionine (Met) and metal chlorides as the precursors and the mesoporous silica (SBA-15) as the hard template. A series of OM-TMS@NCs with a hexagonal mesostructure, ultra-high surface areas (430–754 m²·g^-1), large pore volumes (0.85–1.32 cm³·g^-1), and unique TMS stoichiometries, including MoS₂, Fe₇S₈, Co₉S₈, NiS, Cu₇S₄ and ZnS, are obtained. Two distinct structure configurations, namely, highly dispersed ultrathin TMS nanosheets within NCs and TMS@NC co-nanowire arrays, can be obtained depending on different metals. The structure evolution of the OM-TMS@NCs over the solvent-free nanocasting process is studied in detail for a deep understanding of the synthesis. As demonstrations, these materials are promising for electrocatalytic hydrogen evolution reaction and lithium ion storage with high performances.