“…The C 1s region could be fitted by four peaks centered at 283.6, 284.1, 284.8, and 287.8 eV, which could be assigned to CC, C–O, and CO bonds, respectively. Also, the O 1s region could be fitted by three peaks centered at 530.3, 531.2, and 532.3 eV, which could be assigned to Fe–O, Co–O, and CO bonds, respectively. , The characterizations of other core–shell heterostructures are outlined in the Supporting Information (Figures S6–S18).…”