Engineering amorphous MoS2/RGO hybrid nanoflowers with rich edge sites boost catalytic hydrogen generation

Abstract

To date, the electrolytic water splitting continues to be hindered by its high overpotential and sluggish kinetics of hydrogen evolution reaction (HER). Here, we design a new amorphous MoS₂/reduced graphene oxide hybrid nanoflowers (A-MoS₂/RGO NFs) architecture, in which two-dimensional (2D) few-layer MoS₂ nanosheets are grown on RGO, and assemble into three-dimensional (3D) nanoflowers. The amorphous MoS₂/RGO hybrid nanoflowers have plenty of exposed edge sites, which have been proved to be the catalytic active sites for HER. Besides, the distinctive and robust 3D architecture of amorphous MoS₂/RGO hybrid nanoflowers facilitate the HER by enhancing both mass transport and charge transfer kinetics. The amorphous MoS₂/RGO hybrid nanoflowers exhibit extraordinary HER performance with almost zero onset overpotential, small Tafel slope and extreme high electrochemical durability in wide pH range. The density functional theory (DFT) calculations demonstrate that the charge transfer from RGO to amorphous MoS₂, which increase the charge density of the edge-terminated Mo and S atoms. This unique electronic configuration facilitates efficient H₂O activation and dissociation, the subsequent H* adsorption and conversion processes, thereby significantly enhancing HER performance.