Controllable Sulfurization of MXenes to In‐Plane Multi‐Heterostructures for Efficient Sulfur Redox Kinetics

Abstract Although in‐plane heterostructure with high ion transport pathway and unique interfacial atomic structure offers endless possibilities in the catalysis field, it is still challenging to directly synthesize MXene‐based in‐plane heterostructure due to the differences in crystal structures and growth conditions. Here, Mo 2 C–MoS 2 in‐plane multi‐heterostructures are synthesized by topological conversion of sandwich‐like mesoporous Mo 2 C–SiO 2 layers in sulfur vapor and subsequent removal of SiO 2 . During the conversion process, the exposed Mo 2 C will efficiently converted to 2H phase MoS 2 , meanwhile, the covered Mo 2 C remained stable, affording metallic Mo 2 C MXene and semiconducting MoS 2 in‐plane multi‐heterostructures compatible in one layer. The resultant Mo 2 C–MoS 2 layer has multiple heterointerfaces, build‐in electric fields as well as abundant defects. Such structural features enable to improve of the electrochemical active surface area (16.4 mF cm −2 ), which not only facilitates the bidirectional sulfur electrochemistry between solid Li 2 S and soluble lithium polysulfides, but also enhances the transfer kinetics of electrons and ions, giving rise to a high‐rate performance (642 mAh g −1 at 5 C) and a long‐term cycle life (1000 cycles at 5 C) in lithium–sulfur batteries.