Shape inducer-free polygonal angle platinum nanoparticles in graphene oxide as oxygen reduction catalyst derived from gamma irradiation.

•Polygonal angle PtNPs/NrGO was prepared without using any shape inducer, seed, or template.•Urea, GO and gamma irradiation demonstrated a synergistic effect to PtNPs in polygonal angle shape.•The synergy of restriction effects of GO and crush capacity of high energy gamma rays endows the uniform dispersion and homogeneous size distribution of PtNPs on rGO.•The obtained polygonal angle PtNPs/NrGO exhibit fantabulous ORR activity in alkaline media.