Porous MoS₂ Framework and Its Functionality for Electrochemical Hydrogen Evolution Reaction and Lithium Ion Batteries

A unique porous framework of highly ordered few-layered MoS₂ was realized by using the facile solvothermal technique. The structure was composed of crystalline MoS₂ in the 2H phase, with ordered, 100-150 nm wide pores and a 15 nm wall thickness. The porous framework was studied for electrochemical hydrogen evolution reaction (HER) and rechargeable Li ion batteries. The porous MoS₂ showed enhanced catalytic activity for electrochemical HER, with an overpotential of -210 mV at 10 mA cm^-2. In addition, in Li ion storage testing, the half-cell delivered high specific capacities: 1265 and 1256 mAh g^-1 at 50 mA g^-1 and 1172 and 1161 mAh g^-1 at 200 mA g^-1 for the first discharge and charge with Coulombic efficiencies 99.3% and 99.0%, respectively. The cyclic stability showed a reversible specific discharge capacity of 1178 mAh g^-1 after 100 cycles, which is attributed to the porous MoS₂ framework. An impedance study revealed an improved charge transfer process, attributed to the availability of the channels for the Li⁺ ion intercalation due to the porous framework of the MoS₂. The prima facie observation shows that this unique morphology has significantly improved the performance of such materials without additional modifications, such as doping, indicating that such a porous framework may serve as promising bifunctional electrodes for both energy conversion and storage applications.