Photothermally Enhanced Detoxification of Chemical Warfare Agent Simulants Using Bioinspired Core-Shell Dopamine-Melanin@Metal-Organic Frameworks and Their Fabrics.

Self-detoxifying materials capable of both capture and destruction of chemical warfare agents (CWAs) are highly desirable for efficient personal protection and safe handling of contaminated materials. Developing new strategies to improve CWA removal efficiency of these materials is highly relevant to CWA purification technology. Herein, we present novel photothermally enhanced catalytic detoxification of CWA simulants and its application in self-detoxifying gas filters. The material design features a well-defined core-shell nanostructure (CSN) consisting of an inner photothermal material and an outer microporous catalyst. As a demonstration, the CSN was obtained by growing a Zr-based metal-organic framework (MOF), UiO-66-NH, onto bioinspired dopamine-melanin (Dpa) nanoparticles via heterogeneous nucleation induced by metal chelation. The resultant Dpa@UiO-66-NH CSN has increased the turnover frequency (TOF) of a nerve agent simulant, 4-nitrophenyl phosphate (DMNP), by 2.9- and 1.7-fold in the presence of NIR laser and simulated solar light, respectively. Further incorporation of Dpa@UiO-66-NH CSNs into polymer fibers by electrospinning has led to an even greater photothermal enhancement effect (5.8- and 3.2-fold TOF increase), achieving a faster DMNP degradation rate than the corresponding pure MOF powder for the first time and the shortest half-life of DMNP (1.8 min) among reported MOF-based self-detoxifying fabrics. The significant photothermal enhancement in the detoxification ability of Dpa@UiO-66-NH fabrics is attributed to the instantaneous heat transfer from the photothermal core to the catalytic shell and effective heat retention enabled by the surrounding polymer matrix. The Dpa@UiO-66-NH fabrics can be easily prepared on a large scale and demonstrate efficient protection against DMNP aerosols as stand-alone gas filters. This strategy of photothermally enhanced catalytic detoxification can be feasibly extended to other catalytic detoxification systems and holds promise for next-generation gas masks.