Strain-Modulated Hydrogen Production Performance in Monolayer MoS2 Electrocatalysis Nanodevices

Abstract

The integration of flexible micro- and nanodevices plays a pivotal role in investigating stress-enhanced performances and underlying intrinsic mechanisms for two-dimensional materials. This study presents the fabrication of single-crystal flexible devices using monolayer MoS₂ and its catalytic activities for the hydrogen evolution reaction under stress conditions. A metallic conductive layer was deposited on the photoresist surface via magnetron sputtering, overcoming the challenges associated with lithography on insulating substrates using electron beam lithography (EBL). The results demonstrate optimal etch patterns with a metal modification layer thickness of 10.97 nm. Leveraging this flexible device fabrication process, a single-layer MoS₂ single-nanosheet flexible micro/nano device was developed and subsequently strain-modulated (stretched along the zigzag lattice direction with the armchair lattice direction as the axis). A significant enhancement is observed in the electrocatalytic hydrogen evolution performance as the strain increases from 0 % to 0.40 %. Notably, the onset overpotential decreased from 155.6 to 95.7 mV, and the Tafel slope decreased from 175.3 to 98.6 mV dec⁻¹. This study provides new insights into the design and performance of strain devices for two-dimensional (2D) monocrystalline/polycrystalline materials.