Boosting hydrogen production from alkaline water splitting via electrochemical active surface reconstruction of transition metal sulfide electrocatalysts

Abstract

The development of low-cost catalysts showing high performance for the hydrogen evolution reaction (HER) is very important to enhance alkaline water splitting. Given the rapid advances in the structural design of HER catalysts, here we report a strategy of boosting hydrogen production from alkaline water splitting via electrochemical active surface reconstruction of transition metal sulfide electrocatalysts. Specifically, we prepared a series of MoNiS_3−xO_x (NMSO) catalysts by regulating the electrochemical oxidation conditions and then investigated their structure, morphology, active sites, HER performance, etc. Surface “melting” was observed during the electrochemical reconstruction and the optimal component, 20 s-NMSO, can achieve a current density of 200 mA cm⁻² at an overpotential of only 155.6 mV, similar to the performance of commercial Pt/C catalysts (151.4 mV), and the overpotential at higher current is even lower than that of Pt/C catalysts. Moreover, a large current density of 1 A cm⁻² is achieved at an ultra-low overpotential of 231 mV, with an increase in voltage by only 0.06% after 144 h of chronoamperometric test. The feasibility and effectiveness of the strategy of electrochemical active surface reconstruction can be extended to other materials such as nickel cobalt sulfide catalysts for efficient HER.