Confining polyoxometalates in porphyrin-based porous cationic polymer toward boosting visible-light-driven synthesis of sulfoxides and detoxification of mustard gas simulants

Abstract

Visible-light-driven oxidation of sulfides has attracted the profound attention to synthesize sulfoxides and purify mustard gas simulant. In this work, a series of visible-light-responsive polyoxometalate-based porous cationic polymers, i.e. SiW₁₂-PCP 1, PW₁₂-PCP 2, SiW₁₁-PCP 3, SiW₁₀-PCP 4, SiW₉-PCP 5 (PCP = porphyrin-based porous cationic polymer), were synthesized by ion exchange process. These POM-PCPs exhibit excellent ability of trapping visible light due to their built-in porphyrin units, which can rapidly oxidize sulfides and degrade 2-chloroethyl ethyl sulfide (CEES) in the presence of a 10 W white LED light and O₂. Benefiting from the synergistic effect between [SiW₁₂] and PCP, hybrid 1 has the highest photocatalytic efficiency, attaining 99 % conversion of sulfides within 16 min and 99 % CEES purification in 8 min, much higher than PCP precursor. The reaction mechanism reveals that both O₂^•− and ¹O₂ are involved in the photocatalytic process. What's more, hybrid 1 has remarkable applicability to numerous sulfides and robust six-round recycling with no reduction in catalytic efficiency.