Vacancy-Assisted Fast Electron Transport Non-noble Metal Electrocatalyst Mn 0.09 -MoS 2 for Hydrogen Evolution Reaction

Developing the electrocatalyst with low cost, high efficiency, and environmentally friendly for hydrogen evolution reaction (HER) is important for the goal of high conversion of sustainable energy resources. Herein, a transition metal electrocatalyst named as Mn 0.09 -MoS 2 is designed via a facile route. The successful substituting of Mn allows partial Mo in the original sulfide replaced by Mn and forms Mn-S bond, leading the lattice mismatch of original MoS 2 and large quantities of assisted sulfur vacancies. The high S vacancy structure has the advantages of both morphology and intrinsic chemical properties such as rich vacancy assistance, abundant active sites, and fast electron transfer speed, promoting Mn 0.09 -MoS 2 /NF with excellent HER performance. The density functional theory calculations reveal the intrinsic activation reason that the energy gap of Mn 0.09 -MoS 2 is narrower and the bandgap appears close to the Fermi level, illustrating that Mn substituting can effectively lower the energy barrier for electron transition and promote the electronic conductivity. Benefiting to these advantages, the designed Mn 0.09 -MoS 2 /NF only requires an overpotential of 141 mV to reach 10 mA cm −2 current density with an excellent electrochemical active surface area (1980 cm 2 ) and pretty fast turnover frequency (0.299 s −1 ) in 1 M KOH. This exploration provides a feasible strategy for the controllable preparation and application of transition metal–based electrocatalyst.