▎ 摘　　要

NOVELTY - Preparing graphene-diamond covalent heterogeneous structure connected by covalent bonds comprises using diamond as a substrate and low-melting point metal as a catalyst to cover the surface of the diamond substrate, and using low melting point metals as catalysts. The surface of diamond is converted into graphene by chemical vapor deposition (CVD) reaction after heating, and is connected with the lower diamond substrate in a covalent bond manner. The low melting-point metal are metal elemental gallium or alloy made of gallium, copper, nickel and indium. The method utilizes solid carbon-containing coating on the diamond surface, hydrochloric acid, nitrogen and hydrogen. USE - The method is useful for preparing graphene-diamond covalent heterogeneous structure connected by covalent bond, which is useful in carbon nano material field. ADVANTAGE - The graphene-diamond covalent heterogeneous structure has high quality and few layers of graphene with a set of 1-10, and low defect content in the sheet layer, and can be prepared on any diamond surface, not limited by the diamond substrate shape, size, crystal orientation and other factors and can realize accurate control of graphene sheet growth process by adjusting reaction time, temperature and carbon source. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a graphene-diamond covalent heterogeneous structure.