Dual-Functional Benzotrithiophene-Based Covalent Organic Frameworks for Photocatalytic Detoxification of Mustard Gas Simulants and Antibacterial Defense

Abstract

The persistent threats posed by toxic chemical warfare agents (CWAs) such as mustard gas (bis(2-chloroethyl) sulfide, HD) and bacterial contaminants demand the development of innovative, sustainable mitigation strategies. Photocatalytic processes that generate reactive oxygen species (ROS) offer a promising dual-functional approach for both chemical detoxification and antibacterial defense. In this study, two structurally analogous covalent organic frameworks (COFs), BPY-COF and BD-COF, are synthesized using benzotrithiophene as the donor unit paired with bipyridine and biphenyl, respectively. These COFs exhibit high crystallinity, broad-spectrum light absorption, and efficient charge carrier transport, with BPY-COF demonstrating superior performance due to the incorporation of heteroatoms. BPY-COF achieved ultrafast detoxification of the mustard gas simulant 2-chloroethyl ethyl sulfide (CEES) with a half-life of 35 min and 100% selectivity for 2-chloroethyl sulfoxide (CEESO) under white LED light, outperforming BD-COF. Additionally, electrospun composite fibers containing 40 wt.% BPY-COF maintained comparable CEES degradation rates and exhibited over 99% antibacterial efficiency against Escherichia coli and Bacillus subtilis within 60 min. These findings highlight the potential of BPY-COF as a multifunctional photocatalyst for integrated applications in chemical detoxification and antibacterial defense, addressing critical challenges in public health and safety.