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

Abstract

AbstractAlthough 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, Mo2C–MoS2 in‐plane multi‐heterostructures are synthesized by topological conversion of sandwich‐like mesoporous Mo2C–SiO2 layers in sulfur vapor and subsequent removal of SiO2. During the conversion process, the exposed Mo2C will efficiently converted to 2H phase MoS2, meanwhile, the covered Mo2C remained stable, affording metallic Mo2C MXene and semiconducting MoS2 in‐plane multi‐heterostructures compatible in one layer. The resultant Mo2C–MoS2 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 Li2S 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.