The　combination　of　carbon-based　material　adsorption　and　photocatalytic　oxidation　is　a　crucial　approach　to　eliminate　natural　organic　substances　and　mitigate　membrane　fouling　induced　by　them.　In　this　investigation,　Bi2O3-TiO2　(BT)　was　incorporated　with　three　varieties　of　carbon-based　substances　(such　as　powdered　activated　carbon　(PAC),　ordered　mesoporous　carbon　CMK-3　(OMCs),　and　carbon　nanotubes　(CNTs))　and　employed　as　a　dual-layer　coating　on　the　surface　of　the　ultrafiltration　membrane　to　reduce　membrane　fouling　induced　by　natural　organics　during　the　treatment　of　actual　water　bodies.　Under　light　conditions,　the　BT/CMK-3　coating　outperforms　BT/PAC　and　BT/CNTs　coatings　in　reducing　membrane　fouling,　with　a　flux　recovery　rate　of　up　to　80.4　%　and　an　irreversible　fouling　rate　as　low　as　19.5　%,　while　also　improving　the　removal　rates　of　UV254　and　DOC　to　55.2　%　and　77.9　%,　respectively.　Based　on　the　analyses　of　three-dimensional　fluorescence　PARAFAC　and　liquid　chromatography,　the　BT/CMK-3　coating　efficiently　removes　humic　substances　and　protein-like　compounds　via　adsorption　and　photocatalytic　oxidation,　achieving　a　24.1　%　removal　rate　of　humic　acid　and　a　93.7　%　removal　rate　of　low　molecular　weight　neutral　substances.　Under　the　synergy　of　CMK-3　adsorption　and　BT　photocatalytic　oxidation,　reactive　oxygen　species　effectively　degraded　and　transformed　the　membrane　foulants　enriched　by　CMK-3,　reducing　and　increasing　the　Zeta　potential　and　free　energy　on　the　membrane　surface　to　−4.2　mV　and　15.1mJ/m2,　respectively.　The　interaction　force　between　the　foulant　and　the　membrane　changed　into　a　repulsive　force,　and　the　fouling　mechanism　changed　from　complete　blockage　to　intermediate　blockage,　thereby　shortening　the　transition　time.　This　advancement　provides　significant　promise　for　the　development　and　broader　application　of　photocatalytic　membrane　filtration　technology.　©　2024　Elsevier　B.V.