Optimizing　friction　materials　based　on　molecular　diversity　in　a　molecular　framework　system　is　an　effective　method　to　improve　the　output　performance　of　triboelectric　nanogenerators　(TENGs).　In　this　study,　three　cadmium(II)　metal–organic　frameworks　(Cd-MOFs)　with　different　cavities　were　synthesized　solvothermally　by　the　assembly　of　cadmium　nitrate　(Cd(NO3)2·4H2O),　4′,4′＇＇-carbonylbis(([1,1′-biphenyl]-3,5-dicarboxylic　acid))　(H4CBBD),　and　trans-1,2-bis(4-pyridyl)ethylene　(4,4′-bpe)　via　a　solvent-regulated　strategy.　The　topology　and　porosity　of　Cd-MOFs　could　be　controlled　effectively　by　the　solvent　constituents　and　were　demonstrated　to　be　closely　related　to　their　triboelectric　behaviors.　Theoretical　calculations　and　experimental　characterizations　revealed　that　the　TENGs　fabricated　by　the　Cd-MOF　with　maximum　porosity　exhibited　the　best　triboelectric　performance　owing　to　the　enhanced　specific　surface　area　and　surface　potential.　In　the　applications,　the　high-output　TENGs　can　be　successfully　used　as　an　efficient　power　supply　for　electrochemical　systems,　enabling　the　direct　bromination　of　aromatic　compounds　in　high　yields　with　good　regioselectivity.　This　study　provides　a　simple　and　feasible　method　to　optimize　positive　friction　materials　at　the　molecular　level　and　develops　the　practical　applications　of　TENGs　in　electrochemical　systems.　©　2024　Elsevier　Inc.