▎ 摘　　要

NOVELTY - A multielement co-doped graphene quantum dots comprise graphene quantum dots and two or more elements doped in the graphene quantum dots. The doped two or more elements include an element (E1) and an element (E2). The graphene quantum dots are doped with the element (E2) by plasma treatment in a gas atmosphere containing the element (E2) after the element (E1) is doped. The element (E2) is doped by plasma treatment by placing the graphene quantum dots doped with the element (E1) on a moving stage that reciprocates, rotates, or vibrates in the horizontal direction to uniformly plasma-treat the entire area of the graphene quantum dots. USE - Multielement co-doped graphene quantum dots used as electrocatalyst for water electrolysis and passivation film for supercapacitor electrode (all claimed). Can also be used for battery and fuel cell. ADVANTAGE - The multielement co-doped graphene quantum dots have excellent supercapacitor characteristics in the positive potential range induced by higher electronegativity by activation of electrochemical reaction due to the co-doping effect of multiple elements, and low overvoltage for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), thereby showing improved catalytic activity. The multielement co-doped graphene quantum dots form passivation film on the electrode in an aqueous system to prevent corrosion from aqueous solution, thereby suppressing deterioration of electrode performance and enabling long-term operation. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for manufacturing of multielement co-doped graphene quantum dots, which involves preparing graphene quantum dots, doping the graphene quantum dots with the element (E1), and doping the element (E2) to the graphene quantum dots doped with the element (E1).