Organophosphonate-based nerve agents,
such as VX, Sarin (GB), and
Soman (GD), are among the most toxic chemicals to humankind. Recently,
we have shown that Zr-based metal–organic frameworks (Zr-MOFs)
can effectively catalyze the hydrolysis of these toxic chemicals for
diminishing their toxicity. On the other hand, utilizing these materials
in powder form is not practical, and developing scalable and economical
processes for integrating these materials onto fibers is crucial for
protective gear. Herein, we report a scalable, template-free, and
aqueous solution-based synthesis strategy for the production of Zr-MOF-coated
textiles. Among all MOF/fiber composites reported to date, the MOF-808/polyester
fibers exhibit the highest rates of nerve agent hydrolysis. Moreover,
such highly porous fiber composites display significantly higher protection
time compared to that of its parent fabric for a mustard gas simulant,
2-chloroethyl ethyl sulfide (CEES). A decreased diffusion rate of
toxic chemicals through the MOF layer can provide time needed for
the destruction of the harmful species.
Metal–organic frameworks (MOFs) are promising
candidates
for the catalytic hydrolysis of nerve agents and their simulants.
Though highly efficient, bulk water and volatile bases are often required
for hydrolysis with these MOF catalysts, preventing real-world implementation.
Herein we report a generalizable and scalable approach for integrating
MOFs and non-volatile polymeric bases onto textile fibers for nerve
agent hydrolysis. Notably, the composite material showed similar reactivity
under ambient conditions compared to the powder material in aqueous
alkaline solution. This represents a critical step toward a unified
strategy for nerve agent hydrolysis in practical settings, which can
significantly reduce the dimensions of filters and increase the efficiency
of protective suits.
Perovskites (ABX3) are promising oxygen evolution reaction (OER) catalysts for their highly intrinsic activity. The in‐depth understanding and the adjustment of dynamic reconstruction of active phases for perovskites in OER are still a daunting challenge. Here, a refined A‐site management strategy is proposed for perovskite oxides, which facilitates the surface reconstruction of the B‐site element based active phase to enhance the OER performance. Electrocatalyst LaNiO3 displays a dynamic reconstruction feature during OER with the growth of a self‐assembled NiOOH active layer, based on the in situ electrochemical Raman technology. Precise A‐site Ce doping lowers the reconstruction potential for the active phase and the dynamic structure–activity correlation is well established. Theoretical calculations demonstrate that A‐site Ce substitution upshifts the O 2p level for greater structural flexibility with optimized oxygen vacancy content, thereby activating the B‐site atom and promoting the active phase reconstruction. These results suggest that A‐site management prompts the B‐site element based active phase dynamic reconstruction via engineered X‐site content as a bridge. Therefore, indicating the strong correlation of each‐site component in perovskite oxides during OER and deepening the understanding of the fundamental processes of the structural transformation and further benefiting the accurate design of high‐efficiency perovskite OER electrocatalysts.
The
high chemical and structural diversity of metal–organic
frameworks (MOFs), which are porous crystalline materials, has attracted
significant academic and industrial interest. However, the poor processability
of MOF powders limits their full potential in practical applications.
Toward this end, MOF-based composite materials increase the framework
robustness and subsequent utility. Among these hybrid materials, MOF
composites prepared on commercially available textile fibers offer
the high flexibility needed for important applicationssuch
as heterogeneous catalysis, chemical sensing, pollutant removal, and
drug releasewhile maintaining the functional properties of
MOFs. The ability to further tailor these composites’ shapes
for incorporation into industrial equipment increases their potential
in applications such as adsorption devices and protective gears. In
this Review, we summarize recently reported MOF/fiber fabrication
methods and applications. Our discussion on the advancements and remaining
issues of these production methods segues into several highlighted
applications of MOF/fiber composites, especially within adsorption
devices and protective gears.
The
most recent global health crisis caused by the SARS-CoV-2 outbreak
and the alarming use of chemical warfare agents highlight the necessity
to produce efficient protective clothing and masks against biohazard
and chemical threats. However, the development of a multifunctional
protective textile is still behind to supply adequate protection for
the public. To tackle this challenge, we designed multifunctional
and regenerable N-chlorine based biocidal and detoxifying textiles
using a robust zirconium metal–organic framework (MOF), UiO-66-NH2, as a chlorine carrier which can be easily coated on textile
fibers. A chlorine bleaching converted the amine groups located on
the MOF linker to active N-chlorine structures. The fibrous composite
exhibited rapid biocidal activity against both Gram-negative bacteria
(E. coli) and Gram-positive bacteria (S.
aureus) with up to a 7 log reduction within 5 min for each
strain as well as a 5 log reduction of SARS-CoV-2 within 15 min. Moreover,
the active chlorine loaded MOF/fiber composite selectively and rapidly
degraded sulfur mustard and its chemical simulant 2-chloroethyl ethyl
sulfide (CEES) with half-lives less than 3 minutes. The versatile
MOF-based fibrous composite designed here has the potential to serve
as protective cloth against both biological and chemical threats.
It is challenging to explore a unified solution for the treatment of oily wastewater from complex sources. Thus, membrane materials with flexible separation schemes are highly desired. Herein, we fabricated a smart membrane by electrospinning TiO2 doped polyvinylidene fluoride (PVDF) nanofibers. The as-formed beads-on-string structure and hierarchical roughness of the nanofibers contribute to its superwetting/resisting property to liquids, which is desirable in oil/water separation. Switched simply by UV (or sunlight) irradiation and heating treatment, the smart membrane can realize reversible separation of oil/water mixtures by selectively allowing water or oil to pass through alone. Most importantly, the as-prepared nanofiber membrane possesses outstanding antifouling and self-cleaning performance resulting from the photocatalytic property of TiO2, which has practical significance in saving solvents and recycling materials. This work provides a route for fabricating cost-effective, easily scaled up, and recyclable membranes for on-demand oil/water separation in versatile situations, which can be of great usage in the new green separation technology.
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