Electrochemically induced Fenton reaction of few-layer MoS2 nanosheets: preparation of luminescent quantum dots via a transition of nanoporous morphology

Abstract

Electrochemically induced Fenton (electro-Fenton) reaction was used for efficient and controllable preparation of hydroxyl radicals, leading to the generation of luminescent quantum dots through etching of as-exfoliated MoS₂ nanosheets. Morphologic changes of MoS₂ nanosheets during the electro-Fenton reaction were monitored using transmission electron microscopy, showing that etching of MoS₂ nanosheets induced by hydroxyl radicals resulted in rapid homogeneous fracturing of the sheets into small dots via a transition of nanoporous morphology. The as-generated dots with vertical dimensional thickness of ca. 0.7 nm and plane size of ca. 5 nm were demonstrated to be MoS₂ quantum dots (MoS₂-QDs), and their photoluminescence properties were explored based on quantum confinement, edge effect, and intrinsic characteristics. Moreover, the degree of etching and the concomitant porosity of MoS₂ nanosheets could be conveniently tuned via the electro-Fenton reaction time, resulting in a new morphology of nanoporous MoS₂ nanosheets, with potential new applications in various significant areas.