Effcient production of multi-layer graphene from graphite flakes in water by lipase-graphene sheets conjugation

Abstract

Biographene was successfully produced in water from graphite flakes by a simple, rapid, and efficient methodology based on a bioexfoliation technology. The methodology consisted in the application of a lipase, with a unique mechanism of interaction with hydrophobic surfaces, combined with a previous mechanical sonication, to selectively generate lipase-graphene sheets conjugates in water at room temperature. The adsorption of the lipase on the graphene sheets permits to keep the sheets separated in comparison with othermethods. It was possible to obtainmore than 80% of graphene (in the form of multi-layer graphene) from low-cost graphite and with less damage compared to commercial graphene oxide (GO) or reduced GO. Experimental analysis demonstrated the formation of multi-layer graphene (MLG) mainly using lipase from Thermomyces Lanuginosus (TLL).