▎ 摘　　要

NOVELTY - Preparation of graphene three-dimensional porous composite iron oxide carbon-based material involves adding sodium chloride, carbon source, surfactant and catalyst iron salt to deionized water to form a uniform transparent orange solution, adding catalyst iron salt to deionized water, then adding sodium chloride, citric acid and polyvinylpyrrolidone to deionized water, placing the obtained mixture in refrigerator and freezing, freeze drying in ice to obtain a yellow sample, subjecting the obtained yellow sample to an inert gas atmosphere, annealing and carbonizing to obtain black solid powder, dispersing the obtained powder in deionized water, filtering the sample, injecting deionized water to remove sodium chloride during filtration, drying filtered sample to obtain three-dimensional porous composite iron oxide carbon-based material assembled into graphene-like sheet, mixing obtained material with sulfur, placing the material in a tube furnace, and heating. USE - Preparation of graphene three-dimensional porous composite iron oxide carbon-based material for positive electrode of lithium sulfur batteries. ADVANTAGE - The process produces graphene three-dimensional porous composite iron oxide carbon-based material with excellent pore structure, large specific surface area and excellent electrical conductivity. The process increases the loading of sulfur, and also accelerates the transmission of lithium ions and electrons in lithium-sulfur batteries. DETAILED DESCRIPTION - Preparation of graphene three-dimensional porous composite iron oxide of carbon-based material involves adding sodium chloride, carbon source, surfactant and catalyst iron salt to deionized water at room temperature and stirring for 2-3 hours to form a uniform transparent orange solution, adding catalyst iron salt to deionized water, then adding 7-8 g sodium chloride, 1-3 g citric acid and 0.2-0.3 g polyvinylpyrrolidone to 40 mL deionized water, placing the obtained mixture in a refrigerator and freezing into ice, freeze drying in ice for 60-70 hours to obtain a yellow sample, subjecting the obtained yellow sample to an inert gas atmosphere comprising argon gas, annealing the sample at 600-700 degrees C, and carbonizing for 3-4 hours at a heating rate of 2 degrees C/minute to obtain black solid powder, dispersing the obtained black solid powder in 100-120 mL deionized water, filtering the sample by vacuum suction device, injecting 1000-1500 mL deionized water continuously to remove sodium chloride during filtration, drying the filtered sample at 60-80 degrees C for 10-12 hours to obtain three-dimensional porous composite iron oxide carbon-based material assembled into a graphene-like sheet, mixing the obtained material with sulfur in the mass ratio of 1:3 and grinding the mixture for 30-40 minutes, placing the obtained material in a tube furnace in argon gas for 20-30 minutes, heating the mixture at 155 degrees C for 12-15 minutes, and again heating at 200 degrees C for 25-30 minutes.