High proportion of 1 T phase MoS2 prepared by a simple solvothermal method for high-efficiency electrocatalytic hydrogen evolution

Abstract In this work, defect-rich 1 T-MoS2 nanosheets are successfully synthesized by solvothermal method with acetic acid as the templating agent. It is found that changing the concentration of acetic acid can regulate the proportion of 1 T phase and affect the activity of hydrogen evolution. Under the optimum concentration of acetic acid, the overpotential is as low as 136 mV at the current density of 10 mA cm−2 with a Tafel slope at only 45 mV dec−1, which shows an attractive potential for the development of electrocatalytic hydrogen evolution. In addition, the addition of acetic acid prevents the agglomeration of 1 T-MoS2 and thus increases the stability of electrode materials, which is conducive to the long-term hydrogen evolution reaction and cost control. Most importantly, according to comparing several small molecular carboxylic acids, the probable formation mechanism of 1 T-MoS2 nanosheets is proposed.