1T-2H Crx-MoS₂ Ultrathin Nanosheets for Durable and Enhanced Hydrogen Evolution Reaction

MoS 2 -based materials for hydrogen evolution reaction (HER) were widely reported in recent years. However, the poor conductivity limited the application of MoS 2 . In this paper, we introduced the heteroatom Cr 3+ into the MoS 2 with different weight percent. The property for HER was largely enhanced, especially for the Cr 0.06 -MoS 2 . The overpotential of Cr 0.06 -MoS 2 (0.20 V) was much lower than that of the undoped MoS 2 (0.44 V) at current density of 10 mA cm –2 . What’s more, the Cr 0.06 -MoS 2 also has long time stability (>60 h) and almost 100% Faraday efficiency for water reduction. The enhanced HER activity was mostly due to the increased exposed active sites and shortened passway of electron transfer. For that the ultrathin nanosheets structure of Cr 0.06 -MoS 2 displayed a larger BET surface area (165.52 m 2 g –1 ) than the undoped MoS 2 (130.31 m 2 g –1 ). Besides, Cr 0.06 -MoS 2 showed coexistence of 2H- and 1T-MoS 2 phase after Cr 3+ doping and resulted in much lower data of EIS (16.55 Ω) than the undoped MoS 2 (51.85 Ω). Therefore, the 1T-2H Cr 0.06 -MoS 2 showed enhanced HER activity compared with the undoped MoS 2 and was a supplement of the theoretical calculation.