▎ 摘　　要

NOVELTY - A preparation method of graphene hollow spheres, involves adding (S10) positively charged polystyrene spheres into an aqueous solution containing complexing agent, and mixing uniformly to obtain first mixed solution, adding (S20) negatively charged graphene oxide into the first mixed solution, and uniformly mixing to obtain second mixed solution, adding (S30) carbon nitrogen source into the second mixed solution, and uniformly mixing to obtain third mixed solution, adding (S40) cobalt transition metal salt solution into the third mixed solution, uniformly mixing, gradually adding iron transition metal salt solution, mixing uniformly, carrying out solid-liquid separation and keeping the solid, and drying to obtain brownish yellow powder, and annealing (S50) the brownish yellow powder to obtain a finished product. USE - Preparation method of graphene hollow spheres (claimed) for use as zinc-air battery catalyst. ADVANTAGE - The method provides hollow ball graphene hollow ball with excellent electrochemical ORR activity, nitrogen doping is polarized and change the self-selected density of adjacent carbon atoms, generating a new catalytic activity site, promoting the chemical adsorption of the oxygen molecule, weakens the oxygen-oxygen bond, and finally improves the ORR performance. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for graphene hollow spheres. DESCRIPTION OF DRAWING(S) - The drawing shows a flow chart of the method for preparing graphene hollow spheres. (Drawing includes non-English language text) S10Step to add positively charged polystyrene spheres into aqueous solution containing complexing agent S20Step to add negatively charged graphene oxide into first mixed solution S30Step to add carbon nitrogen source into second mixed solution S40Step to add cobalt transition metal salt solution into third mixed solution S50Step to anneal brownish yellow powder