Solvothermal synthesis of oxygen-incorporated MoS2-x nanosheets with abundant undercoordinated Mo for efficient hydrogen evolution

Activating the inert basal planes of layered molybdenum disulfide (MoS 2 ) is critical to deliver its high hydrogen evolution reaction (HER) efficiency. Herein, oxygen-incorparated MoS x with abundant undercoordinated Mo atoms is fabricated by a facile solvothermal procedure, which realizes synergistically structural and electronic regulations of MoS 2 inert basal planes . Experiment results reveal that oxygen incoparation can effectively modulate the electronic structure and further optimize the intrinsic conductivity, while the defect-rich structure with abundant undercoordinated Mo atoms increases the number of active sites. Moreover, the influence of solvothermal temperature on activity of MoS 2-x is also investigated. The achieved MoS x electrocatalyst prepared at 220 °C exhibits a superior activity for HER with a low overpotential of 191 mV at 10 mA cm −2 , a small Tafel slope of 67 mV dec −1 , and an excellent stability due to the largest surface area and superior conductivity.