Restructuring electronic structure via W doped 1T MoS2 for enhancing hydrogen evolution reaction

The intrinsic electronic structure on the surface of 1T MoS2 makes the non-optimal bonding strength with hydrogen atoms, which is the key factor that the catalytic performance cannot be improved. However, modifying surface electronic structure by doped exotic atom is an effective approach to optimal the bonding strength be-tween hydrogen atoms and 1T MoS2. Herein, this work reports W doped 1T MoS2 with different concentrations by hydrothermal method. The results indicate that W-1T MoS2-15 exhibits excellent catalytic activity for hydrogen evolution reaction (HER), the catalytic activity is better than that of 2H MoS2 and pristine 1T MoS2, the lowest overpotential and tafel slope in acid electrolyte is 292 mV and 55.7 mV dec-1, respectively. Theoretical calculation results show that W-1T MoS2-2/9 has relatively much lower barrier than pristine 1T MoS2 both in Volmer reaction and Heyrovsky reaction. Therefore, W-1T MoS2-2/9 has a faster reaction kinetics for HER. In addition, introducing W atoms can trigger spontaneous electrons redistribution on the basal plane, optimize energy level, and reduce the Gibbs free energy. This study confirmed that doping of atom with similar physical and chemical properties can optimize electronic structure of 1T MoS2 on the basal plane, and effectively improve its electrocatalytic activity.