Ultrafast synthesis of amorphous molybdenum sulfide by magnetic induction heating for hydrogen evolution reaction

Molybdenum sulfides have emerged as viable alternatives to noble-metal catalysts for green hydrogen production via the hydrogen evolution reaction (HER). Herein, magnetic induction heating (MIH) is exploited for the rapid preparation of carbon-supported MoSx nanocomposites. The sample prepared at 200 A for 10 s shows an amorphous Mo3S7Cly-like structure and a low overpotential (η10) of −184 mV at 10 mA cm−2 in acidic media, whereas samples prepared at higher induction currents display a largely crystalline MoS2 structure and drastically lower HER performance. This is due to the formation of dimeric Mo6S14 moieties in amorphous MoSx that is facilitated by the loss of Cl residues during electrochemical reaction and enhanced H adsorption at both the S and Mo sites, in comparison to crystalline MoS2, as shown in First-principles calculations. These results show that MIH may be used as a powerful tool in the preparation of nonequilibrium structures as high-performance electrocatalysts.