Zr(OH)4/GO Nanocomposite for the Degradation of Nerve Agent Soman (GD) in High-Humidity Environments.

Seongon Jang,Dongwon Ka,Youngho Jin,Min-Kun Kim,Heesoo Jung,Hyunsook Jung

doi:10.3390/ma13132954

Abstract

Zirconium hydroxide, Zr(OH)4 is known to be highly effective for the degradation of chemical nerve agents. Due to the strong interaction force between Zr(OH)4 and the adsorbed water, however, Zr(OH)4 rapidly loses its activity for nerve agents under high-humidity environments, limiting real-world applications. Here, we report a nanocomposite material of Zr(OH)4 and graphene oxide (GO) which showed enhanced stability in humid environments. Zr(OH)4/GO nanocomposite was prepared via a dropwise method, resulting in a well-dispersed and embedded GO in Zr(OH)4 nanocomposite. The nitrogen (N2) isotherm analysis showed that the pore structure of Zr(OH)4/GO nanocomposite is heterogeneous, and its meso-porosity increased from 0.050 to 0.251 cm3/g, compared with pristine Zr(OH)4 prepared. Notably, the composite material showed a better performance for nerve agent soman (GD) degradation hydrolysis under high-humidity air conditions (80% relative humidity) and even in aqueous solution. The soman (GD) degradation by the nanocomposite follows the catalytic reaction with a first-order half-life of 60 min. Water adsorption isotherm analysis and diffuse reflectance infrared Fourier transform (DRIFT) spectra provide direct evidence that the interaction between Zr(OH)4 and the adsorbed water is reduced in Zr(OH)4/GO nanocomposite, indicating that the active sites of Zr(OH)4 for the soman (GD) degradation, such as surface hydroxyl groups are almost available even in high-humidity environments.

Highlights

Chemical warfare nerve agents including soman (GD) (O-pinacolyl methylphosphonofluoridate) are known to be the most lethal among chemical warfare agents (CWAs), have been often used in combat zones as tactical weapons and for terrorism during recent decades [1]
Morphological features and chemical composition of as-synthesized Zr(OH)4 /Graphene oxide (GO) nanocomposite and pristine Zr(OH)4 by dropwise method were characterized by using scanning electron microscopy (SEM) images and energy dispersive dispersive spectroscopy (EDS)
Nanocomposite, while small Zr(OH)4 particles agglomerated into large particles in pristine Zr(OH)4

Summary

Introduction

Chemical warfare nerve agents including soman (GD) (O-pinacolyl methylphosphonofluoridate) are known to be the most lethal among chemical warfare agents (CWAs), have been often used in combat zones as tactical weapons and for terrorism during recent decades [1]. Nerve agents have fatal effects in acute phase of poisoning and considerable long-term complications due to irreversible inhibition of acetylcholine esterase [2]. Weapons Convention (CWC), several countries are still stockpiling chemical agents [3]. Effective degradation methods must be prepared in order to protect any important equipment, facilities, and environments from the toxic chemical agents [4,5]. Novel materials making nerve agents decompose into less or nontoxic molecules have been going through noticeable evolutions in recent years [6,7,8,9]. Metal-organic frameworks (MOFs) [10], metal oxides (hydroxides) [11,12], and composite materials [12] have attracted significant attention

Methods

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Discussion

Conclusion