Two-dimensional　carbons　synthesis　through　sustainable　bio-manufacturing　methods　has　attracted　much　attention　in　the　past　decade.　This　process　facilitates　low　cost　and　facile　manufacturing　of　porous　carbon　materials　with　specific　characteristics,　as　well　as　chemical　functions　that　differ　from　their　bulk　counterparts　due　to　the　low　dimensionality.　Herein,　a　unique　graphene-like　carbon　framework　composed　of　three-dimensionally　interconnected　nanosheets　has　been　successfully　fabricated　via　carbonization　of　a　biomass　precursor　guanine　and　colloidal　silica.　The　obtained　two-dimensional　carbon　materials,　consisting　of　carbon　nanosheets　with　varying　sizes,　can　provide　huge　exposed　areas.　Owing　to　the　merits　of　in　situ　nitrogen-doping,　particularly　the　optimization　of　nitrogen　species　and　significant　improvement　in　porosity,　the　sample　GHS-1000-2.5　delivers　the　outstanding　electrochemical　activity　towards　oxygen　reduction　reaction　in　both　acid　and　alkaline　conditions,　which　are　comparable　to　the　commercial　Pt/C　catalyst　and　show　even　better　performance　under　the　same　conditions.　This　highly　efficient,　facile　and　low-cost　strategy　is　expected　to　meet　the　requirements　for　the　commercialization　for　fuel　cells.　©　2019　Wiley-VCH　Verlag　GmbH　&　Co.　KGaA,　Weinheim