Exploring\nFeedstock Recycling in Liquid-Phase-Exfoliated\nNanosheets

Industrial scale-up of two-dimensional (2D) nanomaterial\nproduction\nis essential if these novel materials are to prove themselves commercially\nviable for applications ranging from energy conversion and storage\nto optoelectronic devices and clean water. There are several techniques\nto produce 2D materials, and liquid phase exfoliation (LPE) is one\nthat has emerged as the most widespread across laboratory, pilot,\nand industrial production scales. One of the main issues faced in\nthe scale-up of such techniques is the low yield (typically 0.5–5\nwt %), resulting in high levels of wasted feedstock material. Similarly,\nevery 10 kg of product can create 1000 L or more of solvent waste,\nmany of which are highly toxic to the environment (e.g., NMP). Using\nMoS<sub>2</sub> as a prototypical 2D material, this work demonstrates\na sustainable approach to recover and reuse unexfoliated precursor\nmaterial and the exfoliation solvent to reduce waste by up to 82%\nand solvent requirement by up to 72%. Material production efficiency\nbenefits were also achieved, with over 3-fold increase in product\nyield and energy usage reduced by up to 12%. The approach can be easily\nscaled and immediately implemented using existing infrastructure,\nand a pathway for industrial implementation has been outlined to support\nthis.