Achieving highly efficient electrocatalytic hydrogen evolution with Co-doped MoS₂ nanosheets

MoS₂ is a promising hydrogen evolution reaction (HER) catalyst because of the Pt-like activity at the side edges, but the whole activity is restricted by the inert basal plane. Herein, Co-doped 1T-MoS₂ nanosheets are grown on carbon cloth (CC) through hydrothermal synthesis and exhibit superior HER activity with an overpotential of 69 mV@10 mA cm^-2 and a Tafel slope of 81.84 mV dec^-1 as well as durability for over 100 h at 100 mA cm^-2 in an alkaline medium. The detailed structural tests demonstrate that the improved HER activity is attributed to Co doping and the high 1T phase content. Co doping induces transformation from the 2H to the 1T phase (67%), and further TMA⁺ addition increases the doping amount and the 1T phase content (79%). The excellent durability is due to the strong interface binding between MoS₂ nanosheets and CC associated with the heterogeneous nucleation and growth and the high growth temperature (230 °C). This provides an inspiration for developing efficient and stable MoS₂ catalysts by element doping.