▎ 摘　　要

NOVELTY - Preparing graphene involves performing electrolysis between an electrolysis anode and an electrolysis cathode in a molten carbonate electrolyte to generate carbon nanomaterial on the cathode. The carbon nanomaterial is electrochemically exfoliated from a second anode to produce graphene. USE - Method for preparing graphene. ADVANTAGE - The method enables to prepared graphene, where exfoliating step produces graphene in high yield than thicker, conventional graphite exfoliation reactions, and carbon dioxide can be the sole reactant used to produce the valuable product as graphene, and this can incentivize utilization of carbon dioxide (CO2), and unlike alternative products made from CO2 such as carbon monoxide or other fuels such as methane, use of the graphene product does not release this greenhouse gas back into the atmosphere. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a method for producing carbon nano-platelets, which involves heating a carbonate electrolyte to obtain a molten carbonate electrolyte; disposing the molten carbonate electrolyte between an electrolysis anode and an electrolysis cathode in a cell, where the electrolysis anode and the molten carbonate electrolyte; and applying an electrical current to the electrolysis cathode and the electrolysis anode in the cell to electrolyze the carbonate and generate carbon nano-platelets on the electrolysis cathode without the formation of transition metal nucleation sites on the cathode; (2) a method for producing carbon nano-onions involves heating a carbonate electrolyte comprising an oxide additive to obtain a molten carbonate electrolyte; disposing the molten carbonate electrolyte between an electrolysis anode and an electrolysis cathode in a cell, where the electrolysis anode and the molten carbonate electrolyte do not include a transition metal nucleating agent; and applying an electrical current to the electrolysis cathode and the electrolysis anode in the cell to electrolyze the carbonate and generate carbon nano-onions on the electrolysis cathode without the formation of transition metal nucleation sites on the cathode; and (3) a method for producing graphene carbon nano-scaffolds which involves heating a carbonate salt to obtain a molten carbonate electrolyte enriched in non-lithium carbonates; disposing the molten carbonate electrolyte between an electrolysis anode and an electrolysis cathode in a cell, where the electrolysis anode and/or the molten carbonate electrolyte optionally further comprises a transition metal nucleation agent; and applying an electrical current to the electrolysis cathode and the electrolysis anode in the cell to electrolyze the carbonate and generate carbon nano-scaffolds, where if a transition metal nucleation agent is present, inhibiting activation of the transition metal nucleation agent.