Cathodeactivityplaysanimportantroleintheimprovementofthemicrobialfuelcellsonoceanfloor(BMFCs).AcomparisonstudybetweenRayon-based(CF-R)andPAN-basedcarbonfiber(CF-P)cathodesisconductedinthepaper.Thetwocarbonfiberswereheattreatedtoimprovecellperformance(CF-R-H&CF-P-H),andwereusedtobuildanewBMFCsstructurewithafoamycarbonanode.Themaximumpowerdensitywas112.42mWm-forCF-R-H,followedby66.6mWm-2forCF-R,49.7mWm-2forCF-P-Hand21.6mWm-2forCF-Prespectively.ThehigherspecificareaanddeepgroovemakeCF-RhaveabetterpoweroutputthanwithCF-P.Meanwhile,heattreatmentofcarbonfibercanimprovecellpower,nearlytwo-foldhigherthanheattreatmentofplainfiber.Thisimprovementmaybeduetothequinonesgroupformationtoacceleratethereductionofoxygenandelectrontransferonthefibersurfaceinthethreephaseboundaryafterheattreatment.ComparedtoPAN-basedcarbonfiber,Rayon-basedcarbonfiberwouldbepreferentiallyselectedascathodeinnovelBMFCsdesignduetoitshighsurfacearea,lowcostandhigherpower.Thecomparisonresearchissignificantforcathodematerialselectionandcelldesign.
