Post-oxidation of a fully conjugated benzotrithiophene-based COF for photocatalytic detoxification of a sulfur mustard simulant

Sulfur mustard (HD) poses serious threats to human welfare and homeland security. The detoxification of HD with photocatalysis is highly appealing due to its mild reaction conditions and high selectivity. The structurally tunable and highly porous covalent organic frameworks (COFs) are emerging photocatalysts. COFs show great potential for the detoxification of HD but have seldom been explored. Herein, we propose a facile post-oxidation strategy to enhance the photocatalytic performance of COFs. Through the introduction of sulfone groups, the generation of reactive oxygen species (ROS) is significantly improved, resulting in a 5-fold enhancement for the photocatalytic detoxification of the HD simulant. Furthermore, the oxidized BTT-TPh-COF is successfully processed into free-standing nanofibrous films at a high loading of 40 wt%, which efficiently detoxifies the HD simulant with t_1/2 < 6 min under the simulated sunlight. This work provides a facile strategy to boost ROS generation and realizes the integration of a highly efficient photocatalyst into films.