▎ 摘　　要

NOVELTY - Method for preparing graphene-loaded iron hexagonal nanosheet composite wave-absorbing material involves (a) placing the copper foil substrate in the electrolyte, performing electrochemical polishing, ultrasonically cleaning, blow-drying with argon, placing into a tube furnace for chemical vapor deposition (CVD), (b) transferring the single-layer graphene to silicon/silicon dioxide on the substrate, and placing it into the evaporated sample in room, using high-purity iron particles as the evaporation source, (c) dissolving ferric chloride hexahydrate in ethanol solution, (d) dispersing the cationic surfactant cetyltrimethylammonium bromide and the α-iron oxide hexagonal nanosheet powder in deionized water, (e) adding graphite powder, sodium nitrate, and concentrated sulfuric acid into a three-necked flask, and (f) ultrasonically stirring the surface-modified α-iron oxide hexagonal nanosheet powder and the graphene oxide suspension and mixing, and freeze-drying. USE - The method is used for preparing graphene-loaded iron hexagonal nanosheet composite wave-absorbing material which is used in electromagnetic wave absorption. ADVANTAGE - The method utilizes abundant free electrons in the metal iron nanosheets to realize graphene carrier injection, and fully exerts the dielectric dispersion characteristics of graphene, is simple, uses cost-effective raw material, and realizes large-scale production. DETAILED DESCRIPTION - Method for preparing graphene-loaded iron hexagonal nanosheet composite wave-absorbing material involves (a) placing the copper foil substrate in the electrolyte, performing electrochemical polishing, ultrasonically cleaning, blow-drying with argon, placing into a tube furnace for chemical vapor deposition (CVD), passing in argon, increasing the temperature to 300-310℃, and passing in oxygen, oxidizing the copper foil substrate, turning off the oxygen, passing in hydrogen, controlling the temperature to rise to 1000-1005℃ for 35-40 minutes, controlling the temperature to rise to 1035-1040℃ for 30-35 minutes, maintaining the temperature for 30-90 minutes, and cooling down to 1000-1005℃, increasing the temperature to 1035-1040℃, passing high-purity methane to nucleate and grow graphene, and obtaining single-layer graphene, (b) transferring the single-layer graphene obtained in step (a) to silicon/silicon dioxide on the substrate, and placing it into the evaporated sample in room, using high-purity iron particles as the evaporation source, controlling the background vacuum to 1×10-3Pa, cleaning the evaporation boat, using a film coater to accurately set the thickness of the evaporated iron film, and conducting the evaporation of chromium/gold on the metal electrode to obtain a graphene/iron field effect transistor device, (c) dissolving ferric chloride hexahydrate in ethanol solution, stirring magnetically until completely dissolved, adding sodium acetate to adjust pH to 9-11, and dissolving after complete stirring, transferring to a Teflon autoclave, controlling the temperature at 180-220℃, and conducting a hydrothermal treatment for 18-24 hours, cooling to room temperature, centrifuge and washing with deionized water and absolute ethanol, and drying to obtain α-iron oxide hexagonal nanosheet powder, (d) dispersing the cationic surfactant cetyltrimethylammonium bromide and the α-iron oxide hexagonal nanosheet powder obtained in step (c) in deionized water, and the α-iron oxide hexagonal nanosheet powder, the mass volume ratio of the total mass of tablet powder and cetyltrimethylammonium bromide to deionized water is (4-6)g:(100-200) ml, controlling the temperature of the constant temperature water bath at 60-80℃, stirring for 2-3 hours, washing with deionized water after natural cooling, and drying to obtain surface-modified α-iron oxide hexagonal nanosheet powder, (e) adding graphite powder, sodium nitrate, and concentrated sulfuric acid into a three-necked flask, placing it in an ice bath and stirring mechanically, and controlling the speed of mechanical stirring to 200-400 rpm, adding potassium permanganate during the stirring process, controlling the constant temperature water bath at 35-45℃, and continuously stirring for 1.5-2.5 hours, adding deionized water during the reaction, after the reaction is completed, transferring to an oil bath at 98-105℃, and continuously stirring for 15-20 minutes, cooling down to room temperature, adding deionized water and hydrogen peroxide solution, sealing and storing for standing, using hydrochloric acid with a volume concentration of 10-15% and deionized water to centrifuge and washing to neutrality, after one week of dialysis, adding ionized water and ultrasonically dispersing to obtain a graphene oxide suspension, and (f) ultrasonically stirring the surface-modified α-iron oxide hexagonal nanosheet powder obtained in step (d) and the graphene oxide suspension obtained in step (e) and mixing, and freeze-drying, placing into a tube furnace for thermal reduction, the reducing atmosphere is hydrogen atmosphere or hydrogen-argon mixed atmosphere, and obtaining the graphene-loaded iron hexagonal nanosheet composite wave-absorbing material, and the preparation is completed.