▎ 摘　　要

NOVELTY - Preparing alpha -iron(III) oxide/graphitic carbon nitride modified graphene comprises (i) taking 20 g urea and 2-5 mmol iron salt, grinding and mixing, adding 20 g de-ionized water, grinding for 20-30 minutes, taking 5-10 g graphene in a mortar, continuously grinding, freezing and drying the obtained slurry at -65 degrees C to obtain powder A, (ii) placing the powder A in the crucible with cover, baking in a muffle furnace to obtain the sample B, (iii) taking 0.2-0.3 mmol iron nitrate nonahydrate, 0.1-0.15 mmol 2,5-dihydroxy-1,4-phthalic acid (sic), 3-5 ml N,N-dimethylformamide, 0.1 g isopropanol and 0.1 g de-ionized water in the beaker, stirring for 2-3 hours, then adding the sample B obtained in step (ii), stirring, reacting using microwave radiation heating method, centrifuging and precipitating after finishing reaction, freezing and drying the obtained precipitate at -65 degrees C to obtain the sample C and (iv) roasting the sample C in inert gas atmosphere to obtain final product. USE - The alpha -iron(III) oxide/graphitic carbon nitride modified graphene is useful: as sensitive material for chlorobenzene gas detection (claimed); and as lithium ion battery cathode material, gas catalytic material, photocatalytic material and fuel cell catalyst. ADVANTAGE - The preparation method: is relatively simple, easy to operate and capable of mass production. DETAILED DESCRIPTION - Preparing alpha -iron(III) oxide/graphitic carbon nitride ( alpha -Fe2O3/g-C3N4) modified graphene comprises (i) taking 20 g urea and 2-5 mmol iron salt, grinding and mixing, adding 20 g de-ionized water, grinding for 20-30 minutes, taking 5-10 g graphene in a mortar, continuously grinding for 20-30 minutes, freezing and drying the obtained slurry at -65 degrees C to obtain powder A, (ii) placing the powder A in the crucible with cover, baking in a muffle furnace to obtain the sample B, (iii) taking 0.2-0.3 mmol iron nitrate nonahydrate (Fe(NO3)3.9H2O), 0.1-0.15 mmol 2,5-dihydroxy-1,4-phthalic acid (sic), 3-5 ml N,N-dimethylformamide, 0.1 g isopropanol and 0.1 g de-ionized water in the beaker, stirring for 2-3 hours, then adding the sample B obtained in step (ii), stirring for 1-2 hours, reacting for 3-5 hours using microwave radiation heating method, centrifuging and precipitating after finishing reaction, freezing and drying the obtained precipitate at -65 degrees C to obtain the sample C and (iv) roasting the sample C in inert gas atmosphere to obtain final product. An INDEPENDENT CLAIM is also included for: (1) alpha -iron(III) oxide/graphitic carbon nitride modified grapheme prepared by above method; and (2) use of alpha -iron(III) oxide/graphitic carbon nitride modified grapheme as sensitive material for chlorobenzene gas detection.