Enhanced electrocatalytic hydrogen evolution performance of MoS2 ultrathin nanosheets via Sn doping

Two-dimensional (2D) transition-metal dichalcogenides (TMDs) have drawn much attention due to their unique physical and chemical properties. Molybdenum disulfide (MoS2) is particularly promising in hydrogen evolution reaction (HER) as a substitute for noble-metal catalysts. Although numerous attempts have been made to improve the HER activity of MoS2, engineering the MoS2-based electrocatalysts with activities similar to noble-metal catalysts remains challenging. Herein, we synthesize high-quality tin doped molybdenum disulfide (Sn-MoS2) ultrathin nanosheets by a g-C3N4 sacrificial template assisted thermolytic approach, and detailly investigate the role of Sn doping on the HER activity. The porous Sn-MoS2 nanosheets displays superior HER performance, exhibiting an overpotential of 28 mV at 10 mA cm−2 and a Tafel slope of 37.2 mV dec−1 with an admirable stability. Compared to pristine MoS2 nanosheets, the significantly improved catalytic activity is ascribed to the increased active edge sites, enhanced intrinsic catalytic activity for each active site as well as accelerated electron transfer upon Sn doping. This work may provide guidelines for the design and synthesis of efficient non-precious HER catalysts.