▎ 摘　　要

NOVELTY - Preparing graphene-based carbon nanomaterials comprises: selecting at least one source of carbon, and the electrolytic aqueous solution; saturating the solution with a gas; electrochemical polarization of the source that occurs simultaneously in both electrodes of the electrochemical cell, where the polarization occur through a pre-polarization step and a synthesis step, and the synthesis step occurs at 5-100 mA cm-2 and 500-7200 seconds; and removing the nanomaterials, produced simultaneously in the anodic and cathodic compartments, which are themselves separated by an inert porous barrier. USE - The method is useful for preparing graphene-based carbon nanomaterials which is useful in biosensors, systems for storing and conversion of energy, photocatalysis, fluorescence imaging, and therapeutic and diagnostic systems, e.g. as nanomedicine. ADVANTAGE - The method: produces simultaneously in an aqueous medium two distinct populations of nanomaterials, e.g. based on graphene, with capacitive properties, electrolytic properties and different and adjustable redox properties, without the need for separation processes and chemical modification after synthesis; is a faster method, simpler, with no negative environmental impacts as it does not require oxidizing or reducing agents, corrosive acids and other chemical substances with toxicological potential to oxidize, reduce or dope the nanomaterial; is an easy method to scale up; and is an economically favorable methodology since its implementation does not use costly equipment and infrastructure, being able to use the equipment/infrastructure that already exists. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for graphene-based carbon nanomaterials, where the graphene-based carbon nanomaterials are quantum dots or sp2 amorphous carbon with electrolytic, capacitive and redox properties, in aqueous phase.