Nitrogen-doped carbon active sites boost the ultra-stable hydrogen evolution reaction on defect-rich MoS2 nanosheets

It remains highly challenging to deploy noble-metal-free technologies for commercial hydrogen evolution reaction (HER) catalytic application. A facile strategy is developed in this work to boost the HER activity on non-noble MoS2 catalyst by taking advantage of the platinum-like behavior of nitrogen doped carbon (CN) active sites for catalyzing the process from H+ to H atom. By doping trace amount of CN with the defect-rich MoS2 nanosheet catalyst, the HER activity is significantly improved with the onset HER overpotential reduced to 50 mV, close to the value observed for the platinum catalyst, and the operational overpotential at 10 mA/cm2 decreases by 65 mV. More importantly, with graphite as the counter electrode, stability of the catalyst is substantially improved. No activity decay is detected after 4000 cycles of cyclic voltammetry (CV) sweeping while the overpotential increment of the prisitine MoS2/C catalyst after 2000 cycles CV sweeping is high to ca. 15 mV.