Photocatalytic　ozonation　holds　promise　for　advanced　water　purification,　yet　its　development　has　been　hindered　by　a　limited　understanding　of　ozone　activation　mechanisms　and　its　related　photogenerated　electron　transfer　dynamics.　Herein,　we　employed　in-situ　DRIFTS　and　Raman　spectroscopy　to　elucidate　the　distinct　adsorption　and　activation　behaviors　of　ozone　(O3)　on　the　{001}　and　{110}　crystal　facets　of　Bi2O2CO3　(BOC)　nanosheets.　BOC-{001}　demonstrates　superior　photocatalytic　ozonation　performance,　with　85%　phenol　mineralization　and　excellent　durability,　significantly　outperforming　the　53%　mineralization　rate　of　BOC-{110}.　This　enhanced　activity　is　attributed　to　non-dissociative　ozone　adsorption　and　favorable　adsorption　energy　over　{001}　facet,　which　facilitate　the　one-electron　O3　reduction　pathway.　Furthermore,　crystal　facet　engineering　strengthens　the　built-in　electric　field,　promoting　exciton　dissociation　and　the　generation　of　localized　charge　carriers.　The　synergistic　effects　of　optimized　electron　availability　and　ozone　adsorption　significantly　boost　the　production　of　reactive　oxygen　species.　These　findings　provide　a　deeper　understanding　of　the　critical　roles　of　O3　adsorption　and　electron　transfer　in　radical　generation,　which　could　provide　some　guidance　for　the　strategic　development　of　highly　effective　photocatalytic　ozonation　catalysts.　©　2025　Dalian　Institute　of　Chemical　Physics,　the　Chinese　Academy　of　Sciences