Boosting Alkaline Hydrogen Evolution Activity with Ni‐Doped MoS₂/Reduced Graphene Oxide Hybrid Aerogel

Abstract

Abstract Highly active, durable, and cost‐effective non‐precious‐metal‐based electrocatalysts are urgently needed to improve the sluggish hydrogen evolution reaction (HER) in an alkaline environment. Herein, a lyophilization/thermolysis method is successfully applied to prepare Ni‐doped MoS 2 (Ni‐MoS 2 )/reduced graphene oxide (RGO) hybrid aerogels. The MoS 2 aerogel possesses a higher density of exposed active sites than its corresponding bulk material. Inheriting from GO its abundant functional groups during pyrolysis, the RGO aerogel can uniformly disperse MoS 2 and simultaneously maintain excellent conductivity. The incorporation of Ni atoms can accelerate the cleavage of the HO−H bond and enhance the adsorption and desorption of intermediate OH − . Owing to the synergistic effect of the compositional and structural advantages of aerogels, the Ni‐MoS 2 /RGO hybrid aerogel delivers highly promoted HER kinetics in alkaline media. As a result, an optimal η 10 (overpotential at 10 mA cm −2 ) of 168 mV in 1 m KOH is obtained, which is superior to the non‐doped MoS 2 /RGO hybrid aerogel (225 mV) and MoS 2 aerogel (263 mV), letting alone bulk MoS 2 (448 mV). Moreover, the η 60 (overpotential at 60 mA cm −2 ) is maintained at 262 mV after chronopotentiometry tests at a constant current density of 10 mA cm −2 for 24 h, indicating an exceptionally stability of the HER catalyst.