Maximization　the　synergistic　effect　of　each　component　in　transition　metal-carbon　complexes　is　expected　to　improve　the　bifunctional　oxygen　electrocatalysis　for　rechargeable　Zn-air　batteries　but　is　still　challenging.　Herein,　nucleobase　guanine　is　employed　as　a　supramolecular　precursor　to　generate　the　core　(FeCo　alloy)-shell　(carbon)　structure　embedded　in　ultrathin　graphene-like　nitrogen-doped　carbon　nanosheets　(FeCo@NCNSs)　via　a　confinement　pyrolysis　strategy.　Thanks　to　the　generated　core-shell　structure　and　bimetallic　synergistic　effect,　the　as-prepared　FeCo@NCNSs　exhibits　excellent　electrochemical　performance　in　both　oxygen　reduction　reaction　and　oxygen　evolution　reaction.　As　a　result,　when　served　as　the　bifunctional　air　electrode　for　a　practical　Zn-air　battery,　FeCo@NCNSs　exhibits　a　higher　open-circuit　voltage　(1.553　V)　and　peak　power　density　(197.30　mW　cm-2),　as　well　as　the　greatly　improved　long-term　cyclic　stability　compared　to　the　noble　metal　benchmarks.　This　work　provides　a　promising　approach　to　integrate　various　active　sites　for　bifunctional　oxygen　electrocatalysis　and　inspires　the　exploration　of　simple　but　efficient　electrocatalysts　for　energy　storage　and　conversion.