| Self-detoxifying materials capable of both capture and destruction of chemical warfare agents(CWAs)are highly desirable for efficient personal protection and safehandling of contaminated materials.Developing ne.w strategies to improve CWA removal efficiency of these materials is highly relevant to CWA purification technology.Metal-organic frameworks(MOFs)have recently become one of the most promising materials that can act as both effective adsorbents and heterogeneous catalysts for CWA removal owing to their ultrahigh surface area,rich chemical functionality,and abundant catalytic active sites.The photothermal enhanced catalytic detoxification of CWA combines MOF with a photothermal agent that converts the photon energy provided by the illumination into heat energy to provide additional energy to the reaction system and further promoting the degradation reaction.This is the first time in the field of degradation of CWAs to propose the use of photothermal effect to assist the reaction,which is of great significance for the preparation of efficient protective materials for CWAs.The main findings are as follows:1.Photothermal-enhanced detoxification of CWA simulants using bio-inspired core-shell dopamine-melanin@MOFs and their fabricsIn this part,a well-defined core-shell nanostructure(CSN)consisting of an inner photothermal core and an outer MOF shell were rationally designed.The CSN was prepared by growing Zr-based MOF,UiO-66-NH2.,onto bio-inspired polydopamine(PDA)nanoparticles via heterogeneous nucleation induced by metal chelation.The resultant PDA@UiO-66-NH2 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 PDA@UiO-66-NH2 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 PDA@UiO-66-NH2 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 PDA@UiO-66-NH2 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.2.Bio-inspired polydopamine-mediated MOF fabrics for solar photothermal driven instantaneous detoxification of CWA simulantsIn this part,we employ PDA as a mediating layer for in situ growth of catalytic MOF UiO-66-NH2 on nanofibers/fabrics to achieve high MOF loading with perfect coverage and excellent adhesion.More importantly,we demonstrate that the PDA coating can be used as effective photothermal agent to significantly increase the catalytic degradation rate of DMNP by up to eight times under simulated solar light irradiation.As a result,half-life as small as 0.5 min was realized with the prepared MOF fabric(3 ?mol catalyst loading toward 4?L DMNP).The ultra-fast degradation of DMNP mainly due to efficent heat transfer from the photothermal PDA layer to the outer catalytic MOF layer,which greatly promotes efficient collisions of molecules and the mass transfer rate,the diffusion of the reactants and the active sites continued accessibility,thereby accelerating the rate ofreaction.This work not only provides new insight for integrating MOF catalysts on fabrics for efficient CWA detoxification.and also points to the possible application of bio-inspired PDA in engineering high-performance self-detoxifying textiles by combining its merits of adhesion.metal chelation,and photothermal conversion. |
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