Lowering the sulfur density at the margins to trigger molybdenum disulfide nanoarray growth into branches to boost their hydrogen evolution reaction activity

Abstract

The planting of molybdenum disulfide (MoS₂) nanoarrays on a specific substrate can be realized in 1 minute via dynamic magnetic fields. The high-quality MoS₂ nanoarrays were vertically standing on the substrates. Decreasing the S/Mo ratio can increase the active edges of MoS₂ nanoarrays. Additionally, hydrogen etching favors the increased formation of MoS₂ edges during the growth process. The thus-obtained MoS₂ nanoarrays exhibited excellent HER performance, with a geometric catalytic current density of 100 mA cm⁻² at an overpotential (η) of 238 mV. In addition, the structure of the catalyst electrode remains stable after a 24 hour chronoamperometric (CP) test at 100 mA cm⁻².