▎ 摘　　要

NOVELTY - Square palladium nanosheet comprises a face-centered cubic structure, an exposed crystal faces (100) and directly grown on the surface of graphene oxide. USE - Used as square palladium nanosheet. ADVANTAGE - The method: is simple and controllable. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for producing square palladium nanosheets comprising annealing the sheet-like graphene with an ionic modifier, a palladium precursor, a reducing agent, a dispersant and a solvent and reacting, to obtain the square palladium nano-sheets, where the annealing temperature is 60-120 degrees C and the ionic modifier is bromine ion.