Ionic Liquid‐Intercalated Metallic MoS2 as a Superior Electrode for Energy Storage Applications

Abstract The development of MoS2 in the metallic phase (1T‐MoS2) is of paramount interest as it exhibits superior electrochemical activities compared to its semiconducting polymorph (2H‐MoS2). In this work, an ionic liquid (IL)‐assisted solvothermal method was employed to produce the thermodynamically metastable 1T‐MoS2. Structural characterization of the material suggests the intercalation of the IL into MoS2. De‐intercalation of ILs from 1T‐MoS2 leads to the formation of 2H‐MoS2. Carbon cloth‐supported 1T‐MoS2(1T‐MoS2@CC) shows higher electrocatalytic activity towards acidic hydrogen evolution reaction (HER) by delivering a current density of 50 mA/cm2 at an overpotential of 210 mV whereas 2H‐MoS2@CC requires an overpotential of 260 mV to reach the same current density. In addition, the 1T‐MoS2@CC electrode delivers a high electrochemical double‐layer storage ability compared to 2H‐MoS2@CC in 1 M Na2SO4. The enhanced electrochemical activity of 1T‐MoS2 over 2H‐MoS2 may be due to the existence of conducting basal planes and the high interlayer spacing (about 1 nm) caused by the intercalation of ILs into the MoS2 layers.