Methods of producing graphene nanoplatelets by exposing graphite to a medium to form a dispersion of graphite in the medium. In some embodiments, the exposing results in formation of graphene nanoplatelets from the graphite. In some embodiments, the medium includes the following components: (a) an acid; (b) a dehydrating agent; and (c) an oxidizing agent. In some embodiments, the methods of the present disclosure result in the formation of graphene nanoplatelets at a yield of more than 90%. In some embodiments, the methods of the present disclosure result in the formation of graphene nanoplatelets in bulk quantities that are more than about a 1 kg of graphene nanoplatelets. Additional embodiments of the present disclosure pertains to the formed graphene nanoplatelets. In some embodiments, the graphene nanoplatelets include a plurality of layers, such as from about 1 layer to about 100 layers.