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

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.