The molecule-level photoreactor: accurate embedded iodine-substituted boron dipyrromethene dye within zeolitic imidazolate framework-8 for highly efficient oxidization of sulfides under visible light

Abstract

Using porous metal–organic frameworks (MOFs) as supports for immobilizing dyes as photocatalysts is an important strategy to construct a molecule-level photoreactor. Rational assembly of a heterogeneous photoreactor (photosensitizer + porosity + catalysis) requires individually tailoring based on the structure and function of the dyes and MOFs. Herein we report a facile, one-pot, room-temperature (RT) aqueous solution method to precisely embed an iodine-substituted boron dipyrromethene (I2-BODIPY) photosensitizer within zeolitic imidazolate framework-8 (ZIF-8) cavity. The resultant I2-BODIPY@ZIF-8 composite not only maintained the nanoporous cavity and outstanding stability inherited from ZIF-8 material but also possessed excellent visible-light harvesting property and high singlet oxygen production ability originated from I2-BODIPY dye. Combining the advantages of ZIF-8 material and I2-BODIPY dye, the composite is highly active as a visible light–driven photocatalyst for selective oxidization of aryl sulfides and a sulfur mustard simulant, 2-chloroethyl ethyl sulfide, at RT without overoxidation. Owing to its heterogeneous nature, the composite can be readily recycled at least five times for the oxidization without obvious loss of the catalytic activity.