▎ 摘　　要

NOVELTY - Foamed carbon film is claimed. The thickness of carbon film is 70-200 nm; the interior has a continuous layer of bubbles; the inner wall surface of the bubble is composed of graphene sheet having a sheet spacing of 0.34 nm, the outer wall surface is composed of diamond, and the diamond layer is bonded to the graphene layer; and graphene sheet defects on the inner wall surface are extremely small, and the ID/IG is less than 0.01. USE - The film is useful in sound wave detecting and generating devices. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing foamed carbon film comprising (i) preparing 0.5-10 mu g/ml graphene oxide aqueous solution using graphene oxide, and then using anodized aluminum oxide (AAO) as substrate to obtain membrane having thickness of 200-600 nm, (ii) placing the graphene oxide film attached to the AAO film in a closed container, and fumigating the HI steam at high temperature of 60-100 degrees C for 1-10 hours, (iii) uniformly coating the solid transfer agent on the surface of graphene film, heating at below 5 degrees C below the melting point of the solid transfer agent, and curing the solid transfer agent, (iv) placing the graphene film coated with solid transfer agent at room temperature, and automatically separating the graphene film from AAO film, (v) evaporating the solid transfer agent from the graphene film loaded by the solid transfer agent obtained above at a temperature at which the solid transfer agent volatilizes to obtain independently self-loading reduced graphene oxide film, (vi) spraying a layer of metal including titanium, molybdenum or cobalt on the front and back sides of the reduced graphene oxide film by magnetron sputtering, where molar amount of sputtered metal nanoparticle is not greater than 30% of the molar amount of carbon atoms in the graphene film, (vii) subjecting the graphene film sputtered with metal to chlorination treatment at 800-1200 degrees C, and dispersing the metal nanoparticle in the form of chloride, and (viii) placing graphene film after chlorination in a high temperature furnace, performing high temperature annealing at 2400-3000 degrees C for 1-12 hours to obtain product, where heating rate is not greater than 20 degrees C/minute.