Efficient cathodic exfoliation of graphite in aqueous electrolytes towards high quality graphene for energy and environmental applications

The electrochemical exfoliation of graphite in aqueous medium stands out as an attractive and scalable approach for the production of graphenes for different applications, due to its simplicity, cost-effectiveness and environmental friendliness [1]. In particular, cathodic exfoliation in water should allow access to high quality and non-oxidized graphene flakes, but this possibility has been limited by a poor intercalation ability of aqueous cations [2]. Here, we demonstrate that with a proper choice of starting graphite and electrolyte, high quality graphene flakes can be obtained in substantial yields via cathodic delamination in water.Funding by the Spanish Ministerio de Economia y Competitividad (MINECO) and the European Regional Development Fund (ERDF) through project MAT2015-69844-R and by the Spanish Ministerio de Ciencia, Innovacion y Universidades and ERDF through project RTI2018-100832-B-I00 is gratefully acknowledged. S.G-D. and J.M.M. are grateful to MINECO and the Spanish Ministerio de Educacion, Cultura y Deporte (MECD), respectively, for their pre-doctoral contracts (BES/2016 077830 and FPU14/00792, respectively