▎ 摘　　要

NOVELTY - A method (M1) for preparing graphene using metal oxide involves preparing graphite oxide by treating the surface of graphite with an acid; preparing particles where carbon is bonded to metal oxide by mixing graphite oxide with metal oxide nanoparticles; and separating graphene by treating the prepared particles with an acid. USE - For preparing graphene (claimed) e.g. used in LEDs, in transistor materials, electrode material for secondary cells, super capacitor. ADVANTAGE - The method for preparing graphene allows chemical bonding and separation through simple acid treatment process using inexpensive materials. The processing cost is low and pure graphene with few impurities can be prepared quickly in large scale. Since the particles of quasi metal oxide-graphene core-shell structure obtained as intermediate have graphene shell having very high electron mobility, they have very fast electron transfer rate. Accordingly, with fast response speed and superior optical properties, they may be used in UV sensors, LEDs, and dye-sensitized solar cells (DSSCs), replacing metal-oxide quantum dots or TiO2. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) graphene prepared by the preparation method (M1); and (2) nanoparticles of metal oxide-graphene core-shell structure where graphene surrounds metal oxide nanoparticles and is prepared by reacting graphite oxide with metal oxide nanoparticles