Molybdenum carbide nanoparticles produced by pulsed laser ablation for efficient hydrogen evolution reaction in alkaline conditions

Abstract

Molybdenum carbides have emerged as an optimal alternative to noble expensive materials for hydrogen evolution reaction (HER). Most reported synthesis methods involve prolonged operations at high temperatures in reactive gases environments. In this study, we introduce nanosecond Pulsed Laser Ablation in Liquid (PLAL) as a viable and environmental friendly approach for synthesizing molybdenum carbide by ablating a molybdenum (Mo) target in ethanol. Structural and compositional characterizations on the nanoparticles (NPs) reveal no oxidation and the absence of a graphitic shell, confirming the formation of hexagonal Mo₂C and cubic MoC. The NPs loaded on nickel foam exhibit significant HER activity in an aqueous 1 M KOH electrolyte, with a potential of 136 mV vs. RHE at 10 mA cm^{- 2} and 240 mV at 50 mA cm^{- 2}. The calculated mass activity (0.05 A/cm²) highlights the high intrinsic activity of this material compared to conventional and non-green synthesis methods reported in literature.