Graphene quantum dots assisted exfoliation of atomically-thin 2D materials and as-formed 0D/2D van der Waals heterojunction for HER

Atomically-thin 2D materials have changed the landscapes of many fields. Their applications however are limited by lack of methods for readily and scalable production with high quality. Herein, a simple strategy is reported to exfoliate pristine single or few-layered 2D materials (MoS2, h-BN, WS2, g-C3N4 micro sheets) using bottom-up grown amphiphilic graphene quantum dots (GQDs) as both the intercalation agent and dispersant. Further, it is shown that the as-formed GQD/MoS2 van der Waals heterojunctions (vdWHs) give enhanced performance for electrocatalysis of hydrogen evolution reaction (HER) owing to the synergistic coupling at the 0D/2D heterojunction, delivering a current density of 10 mA cm(-2) at a low overpotential of 160 mV with a small Tafel slope of 56.9 mV dec(-1). In addition to providing a new method for preparing ultrathin 2D microsheets, this study unleashes the application potential of 2D materials and GQD-based 0D/2D vdWHs as non-precious electrocatalysts. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

Thin 2D materials at atomic scale have transformed various fields, but their applications are hindered by the lack of scalable production methods. A new strategy using amphiphilic graphene quantum dots to exfoliate 2D materials and form vdWHs shows enhanced electrocatalytic performance for hydrogen evolution reaction. This study not only provides a new method for preparing ultrathin 2D microsheets, but also reveals the potential of GQD-based vdWHs as non-precious electrocatalysts.