“…To date, several carbon-based resources have been used to synthesise GQDs, such as graphite flakes 16 , carbon nanotubes 17 , graphene 18 , carbon fibre 19 , coal 20 and others 21 , 22 . A number of synthesis techniques have been adopted such as hydrothermal 18 , 23 , electrochemical 24 , 25 , sonochemical 26 , solvothermal 11 , 27 , 28 , laser ablation 29 , microwave cutting 30 , etc. Among these approaches, microwave treatment is indeed beneficial due to its uniform and rapid heating, thereby leading to extremely short reaction time 31 .…”