A method of producing nano-scaled
graphene platelets with an average thickness smaller than 30 nm from a layered
graphite material. The method comprises (a) forming a
carboxylic acid-intercalated
graphite compound by an electrochemical reaction which uses a
carboxylic acid as both an
electrolyte and an intercalate source, the layered
graphite material as an
anode material, and a
metal or graphite as a
cathode material, and wherein a current is imposed upon the
cathode and the
anode at a
current density for a duration of time sufficient for effecting the electrochemical reaction; (b) exposing the intercalated graphite compound to a
thermal shock to produce exfoliated graphite; and (c) subjecting the exfoliated graphite to a mechanical shearing treatment to produce the nano-scaled
graphene platelets. Preferred carboxylic acids are
formic acid and
acetic acid. The exfoliation step in the instant invention does not involve the evolution of undesirable species, such as
NOx and SOx, which are common by-products of exfoliating conventional sulfuric or
nitric acid-intercalated graphite compounds. The nano-scaled platelets are candidate reinforcement fillers for
polymer nanocomposites. Nano-scaled
graphene platelets are much lower-cost alternatives to carbon nano-tubes or carbon nano-fibers.