Sulfur　mustard,　a　highly　toxic　chemical　warfare　agent,　poses　a　significant　threat　to　human　health.　Consequently,　the　development　of　efficient　and　rapid　decontamination　strategies　is　of　paramount　importance.　However,　current　degradation　methods　are　often　hindered　by　slow　reaction　rates　and　limited　selectivity.　Herein,　we　report　a　facile　one-pot　in　situ　self-assembly　method　to　simultaneously　modify　the　photosensitizer　rose　bengal　(RB)　into　both　the　cavities　and　surface　of　zeolitic　imidazolate　framework-8　(ZIF-8),　resulting　in　the　formation　of　the　RB@ZIF-8　composite.　The　RB@ZIF-8　composite　demonstrates　exceptional　singlet　oxygen　(1O2)　photosensitization　capacity,　serving　as　a　visible-light-driven　heterogeneous　photocatalyst　that　enables　selective　oxidation　of　a　sulfur　mustard　simulant　(2-chloroethyl　ethyl　sulfide,　CEES)　to　the　corresponding　non-toxicity　sulfoxide　derivative.　This　system　achieves　complete　conversion　within　6　minutes,　with　a　reaction　half-life　of　2.5　minutes　under　ambient　conditions.　Moreover,　the　composite　demonstrates　outstanding　recyclability　and　reusability.　This　work　provides　a　promising　strategy　for　the　design　of　advanced　MOF-based　heterogeneous　photosensitizers,　offering　a　highly　efficient,　selective,　and　reusable　platform　for　the　rapid　detoxification　of　sulfur　mustard　under　mild　conditions.　©　2025　The　Royal　Society　of　Chemistry.