Selective detoxification of a sulfur mustard simulant in air by a methylene blue functionalized metal-organic frameworks

Abstract

Efficient degradation of a sulfur mustard is essential due to its extreme toxicity and widespread use as a chemical warfare agent. However, current degradation methods often lack selectivity and generate highly toxic by-products. Herein, we demonstrate an approach for the selective photodegradation of a sulfur mustard simulant using singlet oxygen (1O2) produced by methylene blue (MB)-modified a classical metal-organic framework UiO-66-(COOH)2 (abbreviated as UC), specifically the MB@UC composite. The composite was prepared via adsorption of MB on the surface of UC through strong electrostatic interactions. The MB@UC composite demonstrates high 1O2 generation, enabling selective detoxification of a sulfur mustard simulant (2-chloroethyl ethyl sulfide) to the relatively non-toxic sulfoxide with a half-life of 1.8 minutes at ambient conditions. Compared to traditional detoxification methods, the MB@UC composite offers superior selectivity, rapid degradation, and excellent recyclability, maintaining its performance over multiple cycles. This work presents a promising strategy for the development of advanced heterogeneous photosensitizers in the detoxification of chemical warfare agents.