▎ 摘　　要

NOVELTY - Two-dimensional carbon-nitrogen single crystal alloy comprises carbon skeleton of graphene and doping nitrogen atom. The doping nitrogen atom can substitute the carbon atoms in the carbon skeleton of graphene to form two-dimensional super-lattice structure of nitrogen, and the lattice size is 0.4-0.5 nm. USE - Used as two-dimensional carbon-nitrogen single crystal alloy. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the two-dimensional carbon-nitrogen single crystal alloy, comprising (i) treating metal substrate surface to obtain clean and smooth surface; (ii) heating the flat clean surface; (iii) depositing a layer of precursor molecules on the heated surface; and (iv) continuously heating to maintain the temperature to obtain the two-dimensional carbon-nitrogen single crystal alloy, where the precursor molecule for the full halopyridine molecule.