Synthesis of macroscopic monolithic metal-organic gels for ultra-fast destruction of chemical warfare agents

Humidity Enhances the Solid-Phase Catalytic Ability of a Bulk MOF-808 Metal-Organic Gel toward a Chemical Warfare Agent Simulant

Zirconium-based metal-organic frameworks have emerged as promising materials for detoxifying chemical warfare agents (CWAs) due to their remarkable stability and porosity. However, their practical application is hindered by issues with their powder form and poor catalytic performance in solid-phase degradation. To address these challenges, herein, a granular MOF-808 metal-organic gel (G808) is prepared under optimized conditions for catalytic degradation of the simulant 2-chloroethyl ethyl sulfide (2-CEES), a sulfide blister agent, in a neat state under different humidity conditions. The detoxification performance of G808 toward 2-CEES is significantly enhanced as the content of water present increases. The half-life of 2-CEES decontaminated by G808 can be shortened to 816 s, surpassing those of many other benchmark materials. To confirm the mechanism of catalytic degradation, we used gas chromatography, gas chromatography-mass spectrometry, and theoretical calculations. The findings revealed that hydrolysis was the predominant route. Additionally, granular G808 was reusable and adaptable to high-moisture environments, making it an excellent protective material with practical potential.

Metal-Organic Framework Gels for Adsorption and Catalytic Detoxification of Chemical Warfare Agents: A Review

Chemical warfare agents (CWAs) have brought great threats to human life and social stability, and it is critical to investigate protective materials. MOF (metal-organic framework) gels are a class with an extended MOF architecture that are mainly formed using metal-ligand coordination as an effective force to drive gelation, and these gels combine the unique characteristics of MOFs and organic gel materials. They have the advantages of a hierarchically porous structure, a large specific surface area, machinable block structures and rich metal active sites, which inherently meet the requirements for adsorption and catalytic detoxification of CWAs. A series of advances have been made in the adsorption and catalytic detoxification of MOF gels as chemical warfare agents; however, overall, they are still in their infancy. This review briefly introduces the latest advances in MOF gels, including pure MOF gels and MOF composite gels, and discusses the application of MOF gels in the adsorption and catalytic detoxification of CWAs. Meanwhile, the influence of microstructures (pore structures, metal active site, etc.) on the detoxification performance of protective materials is also discussed, which is of great significance in the exploration of high-efficiency protective materials. Finally, the review looks ahead to next priorities. Hopefully, this review can inspire more and more researchers to enrich the performance of MOF gels for applications in chemical protection and other purification and detoxification processes.

Progress in Research and Application of Metal-Organic Gels: A Review

In recent years, metal-organic gels (MOGs) have attracted much attention due to their hierarchical porous structure, large specific surface area, and good surface modifiability. Compared with MOFs, the synthesis conditions of MOGs are gentler and more stable. At present, MOGs are widely used in the fields of catalysis, adsorption, energy storage, electrochromic devices, sensing, analysis, and detection. In this paper, literature metrology and knowledge graph visualization analysis are adopted to analyze and summarize the literature data in the field of MOGs. The visualization maps of the temporal distribution, spatial distribution, authors and institutions' distribution, influence of highly cited literature and journals, keyword clustering, and research trends are helpful to clearly grasp the content and development trend of MOG materials research, point out the future research direction for scholars, and promote the practical application of MOGs. At the same time, the paper reviews the research and application progress of MOGs in recent years by combining keyword clustering, time lines, and emergence maps, and looks forward to their challenges, future development trend, and application prospects.

Array-based chemical warfare agent discrimination via organophosphorus-H2O2 reaction-regulated chemiluminescence

It has been a challenge to achieve rapid, simple, and effective discrimination of organophosphorus nerve agents (typical chemical warfare agents) due to the similar chemical properties of the targets such as sarin, soman, cyclosarin and VX. In this study, we propose a chemiluminescence sensor array that can effectively discriminate organophosphorus nerve agents by organophosphorus-H₂O₂ reaction, which produces peroxyphosphonate intermediate and regulates the chemiluminescence intensity. A simple chemiluminescence sensor array based on different chemiluminescence characteristics of the four organophosphorus nerve agents in the luminol–H₂O₂ system and layered double hydroxide–luminol–H₂O₂ system has been constructed. Four agents can be well distinguished at a concentration of 1.0 mg L⁻¹ when linear discriminant analyses and hierarchical cluster analyses are smartly combined. The high accuracy (100%) evaluation of 20 blind samples demonstrates the practicability of this proposed chemiluminescence sensor array.

A chemical warfare agent sensor array based on organophosphorus-H₂O₂ reaction-regulated chemiluminescence is proposed.

Ultrafast Degradation and High Adsorption Capability of a Sulfur Mustard Simulant under Ambient Conditions Using Granular UiO-66-NH2 Metal-Organic Gels

Zirconium-based metal-organic frameworks (Zr-MOFs) have been considered as prospective materials for the degradation of nerve chemical warfare agents (CWAs) but show poor catalytic performance toward blister agents. Moreover, the powder issues and the poor adsorption capability also remain as the major challenges for the application of Zr-MOFs in practical CWA detoxification. Herein, a series of defected granular UiO-66-NH2 metal-organic gels are synthesized via adjusting the amount of added concentrated hydrochloric acid for the decontamination of 2-chloroethyl ethyl sulfide (2-CEES), a sulfur mustard simulant. The half-life of 2-CEES decontaminated by defected granular UiO-66-NH2 metal-organic gels can be shortened to 7.6 min, which is the highest reported value for MOFs under ambient conditions. The mechanism of decontamination is that the amino group on the linkers in UiO-66-NH2 MOGs undergoes a substitution reaction with 2-CEES to yield 2-(2-(ethylthio)ethylamino)terephthalic acid, which is less toxic and fixed in the frameworks. The recycling test corroborates that the granular UiO-66-NH2 xerogels possess good stability and reusability. Static adsorption and desorption tests show that UiO-66-NH2 xerogels possess a high 2-CEES vapor adsorption capacity of 802 mg/g after exposure for 1 d and only 28 wt % desorption capacity after air exposure for 7 d. The dual function of ultrafast degradation and high adsorption capability provide a firm foundation for using UiO-66-NH2 xerogels as a future protection media.