Dimethyl 4-nitrophenyl Phosphate Research Articles

Ambidextrous approach in action: Mg(OMe)2-doped hierarchical porous zirconium MOFs for decontaminating toxic chemical agents in nonbuffered systems

Utilizing a ligand-truncation strategy, a hierarchically porous structure was engineered within MOF-808, designated as HP-MOF-808. Furthermore, Mg(OMe)2 doping yielded HP-MOF-808@Mg(OMe)2, materials with both hierarchical porosity and basic character, for decontamination of two types of toxic chemical agents in nonbuffered solutions. In aqueous solution, the HP-808-2 exhibited decontamination rate constants for dimethyl-4-nitrophenyl phosphate (DMNP) and the nerve agent soman (GD) that were 3.13 and 1.98 times higher than MOF-808, respectively. The decontamination half-lives of HP-808-2@Mg(OMe)2 1:2 for DMNP and GD were further reduced by 13.87 and 36.82 times compared to HP-808-2. The material retains its decontamination efficacy for DMNP even after 60-days exposure in air and maintains structural integrity in solvents devoid of labile hydrogen for at least 24 h. In methanol, HP-808-2@Mg(OMe)2 achieved 100% DMNP decontamination in 25 min, outperforming HP-808-2 at 31.8%, marking it as the fastest DMNP decontamination material in methanol. Theoretical simulations confirmed the experimental findings, clearly demonstrating the energy changes during reactions with various nucleophiles and revealing the degradation process and mechanism of DMNP on the active sites of MOFs. Moreover, these materials rapidly degraded 2-chloroethyl ethyl sulfide (CEES) through hydrolysis, dehydrohalogenation, and heterolytic cleavage, demonstrating great potential for dual decontamination of toxic chemical agents in unbuffered systems.

Permeable Self-Association of Metal-Organic Framework 808/Ag-Based Fiber Membrane for Broad-Spectrum and Highly Efficient Degradation of Biological and Chemical War Agents.

The threat posed by biological and chemical warfare agents (BCWA) to national security, the environment, and personal health underscores the need for innovative chemical protective clothing. To address the limitations of conventional activated carbon materials, which are prone to falling off and adsorption saturation, an efficient self-association approach was introduced. In this study, we proposed the immobilization of metal-organic framework (MOF) 808 and Ag nanoparticles onto a polypropylene (PP) fiber membrane using a rapid self-association method facilitated by chitosan (CS). The MOF 808/Ag-based (PP-CS/808-Ag) fiber membrane demonstrated exceptional degradation efficiency, achieving a remarkable rate of t1/2 within 2 h for the mustard simulant 2-chloroethyl ethyl sulfide (2-CEES) and a rate of t1/2 = 4.12 min for the G-series simulant dimethyl 4-nitrophenylphosphate (DMNP). A theoretical computational model was developed to determine the overall reaction mechanism, and it was verified that MOF 808 and Ag nanoparticles were mainly involved in the hydrolysis process against 2-CEES and DMNP. The PP-CS/808-Ag composite fiber film was prepared as the core layer, and the fracture strength, bending resistance, and moisture permeability were better than those specified by many countries for biochemical protective clothing, showing that it has a broad application prospect in developing a generation of broad-spectrum bioprotective clothing.

Post‐Synthetic Modification of Mixed‐Metal UiO‐66 Framework for Rapid Neutralization of Chemical Warfare Agent Simulants

AbstractMetal‐organic frameworks (MOFs) are a promising class of materials for catalysis, offering unique opportunities for designing efficient and selective catalysts. In this study, we have focused on the synthesis and catalytic activity of a novel mixed metal MOF, Ce/Zr−UiO‐66@LiOtBu, designed for the rapid hydrolysis of chemical warfare agents simulants: dimethyl 4‐nitrophenyl phosphate (DMNP) and 2‐chloroethyl ethyl sulfide (CEES). This MOF was thoroughly characterized using powder X‐ray diffraction (PXRD), BET surface area, and inductively coupled plasma optical emission spectrometry (ICP‐OES). The catalytic performance of Ce/Zr−UiO‐66@LiOtBu was monitored in the hydrolysis of DMNP and CEES by using 31P NMR and GC‐MS respectively. Remarkably, the MOF demonstrated rapid and efficient catalytic activity, breaking the P−O bond in DMNP with 2 min and the hydrolysis of CEES was observed in less than 45 min The results suggest the potential application of Ce/Zr−UiO‐66@LiOtBu as a robust catalyst in the detoxification of chemical warfare agent simulants. Our findings highlight the novelty of Ce/Zr−UiO‐66@LiOtBu as a catalytically active MOF, showcasing the successful integration of cerium ions and lithium tert‐butoxide to enhance basicity.

Design and development of UiO-67-coated PIM-1-based composites and demonstration of their detoxification performance

Polymer-supported MOF composites have emerged as versatile candidates for various separation and catalytic applications. In this study, we demonstrate design and development of UiO-67-coated Ce(OH)4@PIM-1 composites via dip-coating, drop-casting, solid-phase coating, and supramolecular assembly, and assess their preparation-structure-performance relations. The catalytic performance of the composites was investigated through hydrolysis of dimethyl 4-nitrophenyl phosphate (DMNP), as a nerve agent simulant. The findings revealed that while dip-coating method was unable to achieve a thick and uniform coverage of the MOF layer on the Ce(OH)4@PIM-1, the supramolecular assembly gave rise to 16 wt% MOF loading and the composite prepared via this method exhibited superior catalytic activity by achieving 100% DMNP conversion within 15 min with a half-time of ∼ 4 min at a rate of 0.165 min−1. The enhanced DMNP hydrolysis of the UiO-67-coated Ce(OH)4@PIM-1 composites prepared via supramolecular assembly was driven by the well-connected pore structure and well-dispersed MOF crystals, which enabled greater active sites accessibility. Post-characterization results confirmed that the materials retained their functionality after hydrolysis by exhibiting 100% DMNP conversion efficiency over three cycles. The findings of this study provide valuable insights into the development of advanced protective materials for defense and civilian applications.

Integrating metal-organic framework particles on fabric membranes for decontaminating toxic organophosphates

Zirconium-based metal-organic frameworks (Zr-MOFs) with periodic Lewis acidic nodes have demonstrated impressive catalytic activity in the hydrolysis of organophosphorus nerve agents. Nevertheless, the powdered form of Zr-MOFs and the necessity of a base-buffered aqueous solution during the catalytic reaction pose significant challenges to their practical utilization. In this study, we demonstrate the efficient hydrolysis of an organophosphorus nerve agent simulant, dimethyl-4-nitrophenyl phosphate (DMNP), in both pure water and the solid phase under high humidity conditions, catalyzed by a membrane material. This material, denoted as Im@MOF-808/PVDF, was synthesized through the integration of MOF-808 particles onto PVDF membrane fibers, with imidazole (Im) molecular bases incorporated into the pores of MOF-808. Our findings emphasize the excellent flexibility and processability inherent in Im@MOF-808/PVDF. More notably, it exhibits exceptional catalytic performance in the hydrolysis of DMNP in pure water. Additionally, it demonstrates fair catalytic activity for solid-phase DMNP hydrolysis under high humidity conditions. These features position Im@MOF-808/PVDF as one of the most promising protective materials, showcasing substantial practical applicability.

Mechanically Enhanced Detoxification of Chemical Warfare Agent Simulants by a Two-Dimensional Piezoresponsive Metal-Organic Framework.

Chemical warfare agents (CWAs) refer to toxic chemical substances used in warfare. Recently, CWAs have been a critical threat for public safety due to their high toxicity. Metal-organic frameworks have exhibited great potential in protecting against CWAs due to their high crystallinity, stable structure, large specific surface area, high porosity, and adjustable structure. However, the metal clusters of most reported MOFs might be highly consumed when applied in CWA hydrolysis. Herein, we fabricated a two-dimensional piezoresponsive UiO-66-F4 and subjected it to CWA simulant dimethyl-4-nitrophenyl phosphate (DMNP) detoxification under sonic conditions. The results show that sonication can effectively enhance the removal performance under optimal conditions; the reaction rate constant k was upgraded 45% by sonication. Moreover, the first-principle calculation revealed that the band gap could be further widened with the application of mechanical stress, which was beneficial for the generation of 1O2, thus further upgrading the detoxification performance toward DMNP. This work demonstrated that mechanical vibration could be introduced to CWA protection, but promising applications are rarely reported.

Facile Recycling Strategy of Dyed Polyester Waste by Template-Based Synthesis of UiO-66 for Value-Added Transformation into Self-detoxifying Fabrics.

Polyethylene terephthalate (PET) accounts for a significant portion of textile waste, and recycling strategies for this material have attracted much attention. This study proposes a facile and innovative PET recycling method applicable to environmental remediation that involves the conversion of dyed PET fabric waste into a value-added fabric. Herein, a template-based synthesis approach capable of growing a UiO-66 metal-organic framework (MOF) directly on a dyed PET fabric is reported. The advantage of this process lies in its simplicity, where the partial hydrolysis of PET followed by a zirconium chloride treatment results in the successful growth of UiO-66 on a dyed PET fabric with the concurrent removal of the dye without additional steps. The catalytic performance of the UiO-66-grown fabric was evaluated through the degradation of dimethyl 4-nitrophenyl phosphate (DMNP), a nerve agent simulant. The fabric produced by the simple metal treatment (Zr@PEThyd) exhibited excellent DMNP degradation performance with t1/2 = 43.3 min and maintained functional stability after a harsh washing procedure, an outcome attributed to the surface-assisted UiO-66 growth that ensured good bonding stability. The developed process is innovative in that it uses dyed PET waste as a template for the direct growth of UiO-66, simplifying the process without compromising the catalytic functionality. This research provides an informative option for a sustainable textile recycling strategy by transforming dyed PET waste into an advanced self-detoxifying material.

In-situ adsorption and detoxification of chemical warfare agent simulants by biocompatible Zr-MOFs immobilized ionic liquids composites: Mechanisms, degradation pathways and DFT calculations

Detoxicating materials of chemical warfare agents (CWAs) and their simulants play a critical role in reducing pollution contamination and environmental renovation. In this work, we present a simple strategy to prepare a core–shell structure Fe3O4/UiO-66-NH2/ILs@mSiO2 using hydrogen bonding association and electrostatic forces. We performed disinfection studies on dimethyl 4-nitrophenyl phosphate (DMNP) and 2-chloroethyl ethyl sulfide (2-CEES). The synergistic effects of catalytic activations for CWAs, which reduce the electron transport distance and lower the reaction energy barrier, lead to an increase in hydrolysis and Fenton-like reactions efficiency. Eliminationing tests of DMNP and 2-CEES showed that the half-lives of the degradation reactions were 128.36 and 1.12 min, respectively, and the degradation efficiency did not decrease significantly after 4 cycles. This new type of structure could be magnetically separated within 60 s to facilitate material recovery and reuse. Moreover, the presence of a mesoporous silica shell made the catalyst particles to become biocompatible and environmentally friendly. The degradation pathways of the intermediates were revealed based on nuclear magnetic resonance spectroscopy (NMR), gaschromatography-mass spectrometry (GC–MS) and density functional theory (DFT) calculations. The effective combination of catalysts provided a facile strategy for developing multi-effect synergistic catalysts for the elimination of CWAs and other pollutants.

A MOF-doped molecularly imprinted polymer/MOF hybrid gel incorporating with pH-buffering sodium acrylate for practical detoxification of organophosphorus nerve agents

The fatal toxicity of organophosphorus nerve agents (ONAs) and the realistic condition of chemical attack occurring place trigger the urgent need to develop catalyst materials with degrading ability under the natural environment without bulk water and bases. Here, we strategically design a molecularly imprinted polymer (MIP)/MOF hybrid catalyst material by integrating enzyme-mimic MIP with Zr-MOF UiO-66-NH2 which demonstrate promising catalytic performance for degradation of ONAs. Furthermore, sodium acrylate functions as a hydrophilic and alkaline functional unit together with pyridine-amidoxime based functional monomers (PAAO) to copolymerize into molecularly imprinted polymeric network. The basic sodium carboxylate groups were installed near the active sites to provide appropriate alkaline microenvironment, non-bulk water and acid buffer capacity for the catalysis in pure water. The resultant MIP/MOF composite catalyst demonstrate outstanding catalytic activities in both liquid and solid phase hydrolysis of ONAs. Specifically, the half-life of liquid phase hydrolysis catalyzed by MIP/UiO-66-NH2-0.5 achieves 9.4 min for diethyl-4-nitrophenyl phosphate (DENP) and 10 min for dimethyl 4-nitrophenyl phosphate (DMNP), and solid-state hydrolysis present rapid degradation efficiency with a half-life of 28.6 min. In addition, composite catalyst MIP-Ag/UiO-66-NH2-0.5 that retains substrate selectivity of MIP, enables the simultaneous degradation of two types of organophosphorus substrates (phosphate and thiophosphate) by MIP and MOF in a synergistic way. Summarily, this work displays promising potential of MIP/MOF hybrid enzyme-like catalyst as effective and practical material for the practical protection and detoxification of organophosphorus nerve agents.

Solar-thermally enhanced catalytic hydrolysis of chemical warfare agent simulant with UiO-66-NCS decorated reduced graphene oxide aerogels

As chemical warfare agent (CWA) is one of deadly chemicals with strong toxicity and fast action, it is imperative to develop catalytic protective materials that can quickly adsorb and efficiently detoxify CWAs. Herein, reduced graphene oxide (RGO) aerogels are decorated with UiO-66-NCS metal–organic framework with high catalytic activity by in situ growing UiO-66-NH2 inside the RGO hydrogels, converting the UiO-66-NH2 to more active UiO-66-NCS, and freeze-drying for realizing solar-thermally enhanced catalytic hydrolysis of dimethyl 4-nitrophenyl phosphate (DMNP), a chemical warfare agent simulant. Compared with UiO-66-NH2, the UiO-66-NCS is more efficient in catalytically hydrolyzing DMNP with a 30 % accelerated half-life, and the in situ decoration of the RGO aerogel with UiO-66-NCS further improves the catalytic hydrolysis efficiency because of the more exposed active sites of the UiO-66-NCS. Furthermore, the excellent solar-thermal conversion effect of the RGO porous substrate can rapidly generate heat and transfer it to the UiO-66-NCS catalyst, thereby promoting the catalytic activity of the catalyst. The UiO-66-NCS decorated RGO aerogel exhibits a great detoxification efficiency of DMNP under simulated solar light irradiation with a turnover frequency of as high as 0.0531 s−1, ∼2.3 times higher than that under room light, and 1.5 times better than that of UiO-66-NCS powder. The solar-thermally enhanced catalytic hydrolysis of DMNP with the UiO-66-NCS decorated RGO aerogel is demonstrated by the quick detoxification of CWA simulant with great recyclability.

Construction of imidazole@defective hierarchical porous UiO-66 and fibrous composites for rapid and nonbuffered catalytic hydrolysis of organophosphorus nerve agents

Hydrolytic destruction of toxic organophosphorus nerve agents by metal-organic framework (MOF) catalysts is commonly reliant on bulk water and volatile liquid base, preventing real-world implementation. Poor accessibility to MOF-based active sites in heterogeneous catalysis is also a crucial factor since reactants diffusion is limited by inherently small micropores. To overcome these practical limitations, a ligand-selective pyrolysis strategy was used to construct unsaturated Zr defects and additional mesopores in UiO-66(Zr). Owing to synergistic effect of Zr defects and hierarchical pores, hydrolysis rate constant (k) of nerve agent simulant DMNP (dimethyl 4-nitrophenyl phosphate) on optimal DHP-UiO-30% (defective hierarchical porous UiO-66) is 3.2 times higher than counterpart UiO-30% in N-ethylmorpholine buffer. Encapsulating imidazole (Im) into DHP-UiO-30% affords Im@DHP-UiO, mimicking phosphotriesterase. Im-72@DHP-UiO exhibits rapid DMNP detoxification with 99% conversion in 12 min and initial half-life (t1/2) of 1.8 min in nonbuffered water. As the first example of ‘three-in-one’ detoxifier, Im@DHP-UiO is further integrated onto nonwoven fabric to construct Im@DHP/Fiber, achieving solid-phase detoxification at ambient humidity with t1/2 of 19.6 min and final conversion of 91%. This is comparable to many powdered catalysts in aqueous solution buffered by volatile bases. This unified strategy is critical and viable to efficiently hydrolyze nerve agents in practical settings.

Self-Assembled MOF-on-MOF Nanofabrics for Synergistic Detoxification of Chemical Warfare Agent Simulants.

The development of protective fabrics that are capable of capturing and detoxifying a wide range of lethal chemical warfare agents (CWAs) in an efficient way is of great importance for individual protection gears/clothing. In this work, unique metal-organic framework (MOF)-on-MOF nanofabrics were fabricated through facile self-assembly of UiO-66-NH2 and MIL-101(Cr) crystals on electrospun polyacrylonitrile (PAN) nanofabrics and exhibited intriguing synergistic effects between the MOF composites on the detoxification of both nerve agent and blistering agent simulants. MIL-101(Cr), although not catalytic, facilitates the enrichment of CWA simulants from solution or air, thereby delivering a high concentration of reactants to catalytic UiO-66-NH2 coated on its surface and providing an enlarged contact area for CWA simulants with the Zr6 nodes and aminocarboxylate linkers compared to solid substrates. Consequently, the as-prepared MOF-on-MOF nanofabrics showed a fast hydrolysis rate (t1/2 = 2.8 min) for dimethyl 4-nitrophenylphosphate (DMNP) in alkaline solutions and a high removal rate (90% within 4 h) of 2-(ethylthio)-chloroethane (CEES) under environmental conditions, considerably surpassing their single-MOF counterparts and the mixture of two MOF nanofabrics. This work demonstrates synergistic detoxification of CWA simulants using MOF-on-MOF composites for the first time and has the potential to be extended to other MOF/MOF pairs, which provides new ideas for the development of highly efficient toxic gas-protective materials.

Oxime-Functionalized, Nonwoven Nanofabrics for Rapid, Inexpensive Decontamination of a Nerve Agent Simulant

Organophosphorous-based nerve agents remain one of the most toxic and accessible chemical warfare agents known to man. Herein, we report the development of novel, oxime-functionalized poly(4-vinylpyridine) (P4VP-Ox) materials as inexpensive, scalable polymeric substrates capable of rapid decontamination of nerve agents, as demonstrated using one nerve agent simulant, dimethyl-4-nitrophenyl phosphate (DMNP). The incorporated oximes adjacent to positively charged pyridinium salts remain deprotonated at neutral to slightly basic pH, providing super-nucleophilic materials to deactivate nerve agents and their simulants rapidly and irreversibly. These materials were electrospun to form nanofabrics, providing increased surface area and enhanced reactivity for degradation of DMNP. Nanofibers obtained from P4VP functionalized at 20 mol % pendants with ortho-pyridinium oximes moieties (P4VP-OOx20%) provided the fastest reaction kinetics. This substrate provided complete decomposition of DMNP within 1.5 h and calculated t1/2 = 14.4 min. The P4VP-Ox substrates were also found to be recyclable, allowing for quantitative DMNP degradation within 8 h over the course of four reaction cycles. Furthermore, to mimic real-life scenarios, we attempted solid-state DMNP degradation via applying small drops of DMNP directly on the nanofabric substrates and extracting with water for 31P NMR analysis. Overall, the P4VP-OOx20% substrate was found to retain its reactivity in the solid state, with the as-prepared nanofabric displaying >95% DMNP degradation after 6 h. When performed in different environments (i.e., 100% humidity, hexanes-rich atmosphere), the reactivity diminished slightly but still displayed >95% degradation after 24 h of reaction, establishing these materials for applications as reactive, economical, and easily scalable Chem-Bio protective materials.

Spontaneously super-hygroscopic MOF-gel microreactors for efficient detoxification of nerve agent simulant in atmospheric environments

We design a spontaneously super-hygroscopic alkaline microreactor by photoinduced integration of Zr-MOF catalyst and alkaline poly(dimethylaminoethyl acrylate) onto LiCl-salinized poly(N-isopropylacrylamide) gel, generating a microenvironment with non-volatile polymeric base and non-bulk water for detoxification of a typical nerve agent simulant, dimethyl 4-nitrophenyl phosphate (DMNP), in atmospheric environments. The super-hygroscopic gel with directional microchannels facilitates the absorption, transport and storage of water under different humidities, and exhibits fast hygroscopic efficiency with a high moisture absorption capacity of 6.4 g g−1. The integrated microreactor achieves simultaneous water uptake and catalytic hydrolysis of DMNP in an atmospheric environment with an initial half-life of ∼1.9 h and a final conversion of 95.5%, which is attributed to the synergistic catalytic microenvironment of the exposed Zr-MOF catalyst, the polymeric base, and the water from moist air. This work provides a feasible strategy for designing spontaneously hygroscopic microreactors for detoxifying nerve agent simulants in atmospheric environments.

Dual-Function Detoxifying Nanofabrics against Nerve Agent and Blistering Agent Simulants

The development of functional materials that can detoxify multiple chemical warfare agents (CWAs) at the same time is of great significance to cope with the uncertainty of CWA use in real-world situations. Although many catalysts capable of detoxifying CWAs have been reported, there is still a lack of effective means to integrate these catalytic-active materials on practical fibers/fabrics to achieve effective protection against coexistence of a variety of CWAs. In this work, by a combination of electrospinning and in situ solvothermal reaction, PAN@Zr(OH)4@MOF-808 nanofiber membranes were prepared for detoxification of both nerve agent and blistering agent simulants dimethyl 4-nitrophenyl phosphate (DMNP) and 2-chloroethyl ethyl sulfide (CEES). Under the catalytic effect of the MOF-808 component, DMNP hydrolysis with a half-life as short as 1.19 min was achieved. Meanwhile, an 89.3% CEES removal rate was obtained within 12 h by adsorption and catalysis of MOF-808 and Zr(OH)4 components at ambient conditions, respectively. PAN@Zr(OH)4@MOF-808 nanofiber membranes also showed a superior blocking effect on CEES compared to bare PAN and PAN@Zr(OH)4 nanofiber membranes. Simultaneous protection against DMNP and CEES showed effective inhibition of both simulants for at least 2 h. The preparation method also imparted intrinsically good interfacial adhesion between the components, contributing to the excellent recycling stability of PAN@Zr(OH)4@MOF-808 nanofiber membranes. Therefore, the prepared composite nanofabrics have great application potential, which provides a new idea for the construction of broad-spectrum protective detoxification materials.

Zirconium-based MOF nanocrystals confined on amphoteric halloysite nanotubes for promoting the catalytic hydrolysis of an organophosphorus nerve agent simulant.

Exploiting efficient and practical catalysts for hydrolyzing organophosphorus nerve agents is significant and highly desirable. Herein, a new class of self-detoxifying composites, namely, halloysite nanotubes@NU-912 (HNTs@NU-912), HNTs@NU-912-I and HNTs@UiO-66-NH2, is constructed by in situ synthesis of hexanuclear zirconium cluster-based metal-organic frameworks (Zr-MOFs) NU-912, NU-912-I and UiO-66-NH2, respectively, with HNTs, which are natural nanotubular materials consisting of Si-O-Si tetrahedral sheets on the outer surface and Al-OH octahedral sheets on the inner surface. The results show that crystalline Zr-MOFs uniformly cover the outer surface of HNTs and the particle size of Zr-MOFs is greatly reduced to less than 50 nm. Furthermore, HNTs@NU-912, HNTs@NU-912-I and HNTs@UiO-66-NH2 display much higher catalytic efficiency for the hydrolysis of dimethyl-4-nitrophenyl phosphate (DMNP) than the corresponding Zr-MOFs both in an aqueous N-ethylmorpholine (NEM) buffer solution and under ambient conditions. Specifically, HNTs@NU-912-I shows a turnover frequency (TOF) of 0.315 s-1 in aqueous buffer solution, placing it among the best Zr-MOF-based heterogeneous catalysts for the hydrolysis of DMNP. The composites show high stability, and more importantly, can replace the buffer solvent and control the pH to a certain degree by virtue of its acidic Si-O-Si sheets and alkaline Al-OH sheets. This work provides a certain reference for the subsequent development of personal protective equipment.

ZnFe2O4/ZrO2/NaX zeolite nanocomposite catalyst: elaboration and its application for the removal of dimethyl 4-nitrophenyl phosphate (DMNP) chemical nerve agent simulant from water solution

ZnFe2O4/ZrO2/NaX zeolite nanocomposite catalyst: elaboration and its application for the removal of dimethyl 4-nitrophenyl phosphate (DMNP) chemical nerve agent simulant from water solution

Rational Design of a Zr-MOF@Curli-Polyelectrolyte Hybrid Membrane toward Efficient Chemical Protection, Moisture Permeation, and Catalytic Detoxification.

Developing high-performance protective materials is important for soldiers and civilians who are exposed to the atmosphere of highly toxic chemical warfare agents (CWAs). Polyelectrolyte membranes are promising candidates with excellent chemical resistance and moisture permeability, but they cannot efficiently degrade CWAs. Here, we design and prepare a hybrid membrane through in situ growth of catalytically active zirconium-based metal-organic frameworks (Zr-MOFs) on a polyelectrolyte membrane mediated by biofilm-inspired curli nanofibers (CNFs). Superior to the bare polyelectrolyte membrane, the prepared MOF-808@CNF-PQ hybrid membrane exhibits improved rejection of the nerve agent simulant dimethyl methyl phosphonate (DMMP) vapor and permeation of the water vapor by 113 and 45%, respectively. The water/DMMP selectivity of the hybrid membrane reaches 498.6, approximately 13 times that of the commercial polyelectrolyte membrane Nafion 117. In addition, the hybrid membrane possesses appreciable catalytic activity for the hydrolysis of the nerve agent simulant dimethyl 4-nitrophenyl phosphate (DMNP) with a half-life of ∼38 min. Nanomechanical characterization results based on atomic force microscopy (AFM) techniques demonstrate the critical role of CNFs in mediating Zr-MOF nucleation and the dominant effect of electrostatic interactions on self-assembly of CNFs on polyelectrolyte base. It is also confirmed that the Zr-MOF toppings serve as the key components in physically adsorbing and chemically degrading the DMNP molecules through multiple strong intermolecular interactions. Our work offers a rational strategy to develop advanced membranes toward efficient chemical protection, moisture permeation, and catalytic detoxification against CWAs.

Construction of hierarchically porous metal-organic frameworks via vapor atmosphere etching

Developing a versatile etching strategy for constructing hierarchically porous metal-organic frameworks (HP-MOFs) with anticipated mesopores and micropores remains a crucial scientific challenge in probing the enhanced performance and potential applications of MOF materials. Herein, a universal vapor etching method is implemented to controllably create HP-MOFs. Based on the principle that the concentration of vapor is lower than that of the solution, the etching rate and strength toward MOFs are greatly reduced, enabling us to obtain intermediate products during etching. Using this strategy, a series of desired HP-MOFs with varying metal nodes have been prepared. The resultant HP-MOFs integrate the merits of mesopores (mass transfer facilitation) and micropores (large internal surface area). For the degradation of the nerve agent, dimethyl 4-nitrophenyl phosphate, HP-UiO-66 exhibits better catalytic activity than pristine UiO-66.

Aggregation-Suppressed Porous Processable Hexa-Zirconium/Polymer Composites for Detoxification of a Nerve Agent Simulant

We describe a composite in which reactive hexa-nuclear zirconium (Zr6) clusters were encapsulated in the micropores of processable polymers of intrinsic microporosity (PIMs). By varying the amount of Zr6 clusters in PIMs, it was possible to tune the loading of Zr6 in two polymer matrices: the pristine PIM-1 and the amidoxime-functionalized PIM (PIM-1-AO). Aggregation of Zr6 clusters was suppressed in both Zr6@PIM composites to achieve improved hydrolysis performance of a nerve agent simulant, dimethyl 4-nitrophenylphosphate (DMNP). Low-loading Zr6@PIM-1-AO was found to be the best catalyst, with a DMNP hydrolysis half-life of less than 1 h, which is comparable to some zirconium metal–organic frameworks (Zr-MOFs) at higher catalyst loading. Further, these composites can be electrospun into reactive nanofibers. This demonstrates a new route to apply porous polymers as matrices to encapsulate, stabilize, and utilize the reactivity of soluble Zr6 clusters, which could act as effective candidate materials for the fabrication of personal protective equipment (PPE) against nerve agents.