Nickel-doped two-dimensional molybdenum disulfide for electrochemical hydrogen evolution reaction

Ni-doped MoS2 was developed by facile solvothermal route. Ni2xMo1-xS2 with x = 0.05 emerged as a superior electrocatalyst with a current density value of - 405 mA cm(-2) at an overpotential of - 200 mV vs. RHE. The catalyst efficiency index namely eta(10) was obtained to be - 133, - 68, - 70, - 80 and - 128 mV for x = 0, 0.05, 0.1, 0.15 and 0.2, respectively. This value indicates that at lower overpotential three compositions (x = 0.05, 0.1, 0.15) was equally efficient but with increase in overpotential x = 0.05 in Ni2xMo1-xS2, outstand the rest. The turn over frequency (H-2/s) at eta = - 100 mV vs. RHE for Ni2xMo1-xS2 with x = 0, 0.05, 0.1, 0.15 and 0.2 were calculated to be 0.3, 3.5, 2.0, 1.1 and 0.6, respectively. The prime reason for the enhanced performance is attributed to the increase in the number of active sites and electronic modulation due to the synergistic effect of MoS2, NiS and Ni3S4. Graphic abstract

Automated summary

Ni-doped MoS2 synthesized by a facile solvothermal method exhibited superior electrocatalytic performance, with Ni2xMo1-xS2 at x = 0.05 showing the best efficiency and highest number of active sites. This enhanced performance is attributed to the synergistic effect of MoS2, NiS, and Ni3S4 leading to increased electronic modulation and active sites.