Developing,　a　highly　efficient,　cost-effective,　easily　scalable　and　sustainable　cathode　for　oxygen　reduction　reaction　(ORR)　is　a　crucial　challenge　in　terms　of　future　＂green＂　energy　conversion　technologies,　e.g.,　microbial　fuel　cells　(MFCs).　In　this　study,　a　natural　and　widely　available　lotus　leaf　with　intrinsically　hierarchical　structure　was　employed　to　serve　as　the　single　precursor　to　prepare　the　catalyst　applied　as　the　MFC　cathode.　The　hierarchically　particle-coated　bio-carbon　was　self-constructed　from　the　lotus　leaf,　which　yielded　a　large　specific　surface　area,　highly　porous　structure　and　superhydrophobicity　via　facile　pyrolysis　coupling　hydrothermal　activation　by　ZnCl2/(NH4)(2)SO4.　Electrochemical　evaluation　demonstrated　that　these　natural　leaf-derived　carbons　have　an　efficient　ORR　activity.　Specifically,　the　HC-900　catalyst　with　hydrothermal　activation　achieved　an　onset　potential　of　-0.015　V　vs.　Ag/AgCl,　which　was　comparable　to　the　commercial　Pt/C　catalyst　(-0.010　V　vs.　Ag/AgCl)　and　was　more　efficient　than　the　DC-900　catalyst　through　direct　pyrolysis.　Furthermore,　the　HC-900　catalyst　achieved　an　outstanding　ORR　activity　via　a　one-step　and　four-electron　pathway,　exhibiting　a　potential　alternative　to　Pt/C　as　electrocatalyst　in　ORR,　due　to　its　better　long-term　durability　and　methanol　resistance.　Additionally,　the　HC-900　catalyst　was　applied　as　an　effective　electrocatalytic　cathode　in　an　MFC　system　with　a　maximum　power　density　of　511.5　+/-　25.6　mW.m(-2),　exhibiting　a　superior　energy　harvesting　capacity　to　the　Pt/C　cathode.　(C)　2019　Elsevier　B.V.　All　rights　reserved.