NOVELTY - Leaf-shaped heteroatom doped aerogel carbon nanomaterial comprises basic structural unit assembled together with its heteroatom doped lightweight porous material. The leaf-shape basic structural unit comprises leaf-shaped carbon nanotubes, carbon nanotubes stripped off graphene nanoribbons simulation blade, or graphene nanoribbons seamless bridging hybrid structure. The heteroatom doped lightweight porous material comprises nitrogen, phosphorus, boron, or sulfur.    USE - Leaf-shaped heteroatom doped aerogel carbon nanomaterial used as electrode material or cathode material for catalytic oxygen reduction fuel cell (claimed).    ADVANTAGE - The leaf-shaped heteroatom doped aerogel carbon nanomaterial shows better catalytic performance than commercial platinum/carbon material.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of leaf-shaped heteroatom doped aerogel carbon nanomaterial by:    (A) preparing leaf-shaped carbon nanomaterial precursor solution by adding 1 g carbon nanotubes into 20-500 ml concentrated sulfuric acid; stirring for 1-12 hours to dispersed; adding 10-500 ml phosphoric acid; further stirring at room temperature for 1-2 hours; slowly adding different amounts of potassium permanganate, or counterion oxide cutting carbon nanotubes, in which potassium permanganate is added at 0.50 g/hour, mass ratio of potassium permanganate and carbon nanotubes is (1-5):1, counterion oxide includes potassium nitrate or potassium sulfate, and amount of carbon nanotube is 1-10 times; stirring reactants at room temperature in oil bath for 1-24 hours; continue reacting for 10 minutes to 24 hours at 20-200 degrees C; cooling reaction solution; adding ice water and hydrogen peroxide; standing overnight; treating with 5% hydrochloric acid twice; centrifuging; dialyzing lower sediment using ultrapure water at 3500 Da using dialysis bag for 1-30 days, in which ice water and hydrogen peroxide are added at 20-2000 ml and 10-100 ml, respectively; taking out reactant; and adding water and standing for 1-24 hours to obtain brown transparent liquid, i.e. leaf-shaped carbon nanomaterial precursor solution;    (B) adding water in leaf-shaped carbon nanomaterial precursor solution of different dopants; hydrothermally reacting at 80-200 degrees C for 1-48 hours to obtain uniform leaf-shaped carbon nanomaterial hydrogel, in which 10 ml of 0.1-50 mg/ml leaf-shaped carbon nanomaterial precursor solution is added with 1-100 wt.% soluble dopant;    (C) drying nanomaterial hydrogel to obtain leaf-shapes carbon aerogel nanomaterial; and    (D) subjecting leaf-shaped carbon aerogel nanomaterial into high temperature pyrolysis under protection of inert gas to obtain leaf-shaped heteroatom doped aerogel carbon nanomaterial.