Graphene is a two-dimensional carbon material with unique chemical, electrical and mechanical properties that has a wide range of potential applications in various fields. One of the most effective methods of producing graphene is liquid phase exfoliation (LPE), in which bulk graphite is broken down into its individual layers while suspended in a suitable suspension medium ('solvent'). However, this exfoliation process can be challenging due to the complex effects of the solvent system on exfoliation, dispersibility and yield.

To overcome these challenges, and extending previous findings by Arao et al.[1], we have developed a highly efficient method for exfoliation of graphite to graphene using a cosolvent system of low boiling point organic solvents in combination with water and ammonia (NH3) as surfactant/additive. Our method results in high yields of graphene and, importantly, all suspension components including the ammonia surfactant/additive are also readily removable. Our work thus demonstrates a facile route to improved graphene LPE yields by introducing a very easily removable surfactant/additive (NH3) in a wide range of solvent mixtures (including low boiling point and benign mixtures), thus providing a framework for simpler, more flexible and safer 2D graphene LPE development.