Synthesis of Manganese Silicide Nanowires by Thermal Chemical Vapor Deposition for the Hydrogen Evolution Reaction

Thermalchemical vapor deposition investigated the growth-alignedmanganese silicide (MnSi) nanowires on a c-Si(111) substrate. Thegrowth, composition, and morphology of MnSi nanowires were studiedin detail using X-ray diffraction, transmission electron microscopy,field emission electron microscopy, and X-ray photoelectron spectroscopyat different reaction pressures (0.03, 0.12, 0.52, 1.20, and 6.20mbar). The effect of reaction pressure on the electrocatalytic activityof MnSi nanowires in the hydrogen evolution reaction (HER) was exploredfurther. Compared to higher pressure, at lower pressure (0.12 mbar),the as-synthesized MnSi nanowire exhibits the greatest electrocatalyticperformance (1.2 mbar). The electrochemical impedance spectroscopyanalysis revealed that the increase in HER electrocatalytic activityof MnSi nanowires at a lower reaction pressure of 0.12 mbar is associatedwith increasing number of charge carriers transported by a reducingdiameter of the nanowires, which is a function of the reaction pressure.

Automated summary

Thermalchemical vapor deposition was used to grow aligned manganese silicide (MnSi) nanowires on a c-Si(111) substrate. The growth, composition, and morphology of MnSi nanowires were characterized using various techniques. The electrocatalytic activity of MnSi nanowires in the hydrogen evolution reaction (HER) was found to be highest at lower reaction pressure (0.12 mbar). This increase in activity was attributed to an increase in charge carrier transport due to the smaller diameter of the nanowires.