Simple, low cost method developed for large scale graphene production

According to the team from the Institute of Physical Chemistry of the Polish Academy of Sciences (IPC PAS) and the Interdisciplinary Research Institute in France, the most complex apparatus used in their method is an ultrasonic cleaner – a piece of equipment common in most laboratories. "If we are thinking about industrial applications of graphene, we have to find better controlled methods for producing this material in a large scale, without using expensive, specialised equipment," commented Izabela Kaminska, a PhD student from the IPC PAS. The process involves mixing graphene oxide with a compound called tertathiafulvalene (TTF) and then placing it in the ultrasonic cleaner. The interactions between the TTF rings and the graphene oxide rings result in a reduction of graphene oxide to graphene with a simultaneous oxidation of the TTF molecules. A composite is obtained containing graphene flakes with TTF molecules intercalated into them. Drying the solution on an electrode creates a smooth surface of graphene flakes with controllable thickness from 100 to 500nm. The final stage is to expel the TTF molecules through a simple chemical reaction. "One of our motivations for the research was to look for new methods for detecting biological substances," added Prof Marcin Opallo. The team discovered that after expelling TTF from the graphene, it could be reincorporated into the matrix. "Therefore it is possible to develop a process allowing one to bind a selected compound to a TTF molecule, and then to incorporate the entire complex into a graphene sheet on an electrode and monitor the electric current flow," concluded Opallo.