Controlled Building Mesoporous MoS2@MoO2-Doped Magnetic Carbon Sheets for Superior Potassium Ion Storage
Molybdenum disulfide (MoS2) has attracted intensively attention as a candidate for potassium ion storage. However, the MoS2 anode material is confined by the poor electron conductivity, the poor structural stability due to large volume variation, the growth of potassium dendrites and the sluggish chemical kinetics. The combination of optimizing phase morphology, element composition, and surface nanostructure is effective for solving these problems. Herein, Fe was firstly encapsulated into the porous biomass derived carbon (CN) during the Fe-catalyzed post annealing process and subsequently MoS2@MoO2 was well wrapped into such porous N doped carbon matrix (CN), the prepared MoS2@MoO2@Fe@CN was evaluated as the anode material for potassium ion batteries (KIBs).The growth mechanism of e MoS2@MoO2@Fe@CN was well studied and the synthesis conditions were explored. The encapsulated metallic Fe into the carbon frame work and its intimate integration with the heterojunction of MoO2@MoS2 facilitate the transportation of electrons and ions, supplying the favorable mass transfer. The low energy barrier for K+ insertion/extraction into the Mo-S-O and N-Mo-O channels is brought primarily because of the well waved heterojunctions with elevated electron densities. Density functional theory (DFT) displays the internal electrical field guides the electron transfer from MoO2 to MoS2 at the interface, decreasing the K+ adsorption energy and migration barrier. This work supplies a guidemap to synthesize a heterojunction to enhance both the electrochemical performance and stability of MoS2-based electrode material for effective energy storage.