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

• Main Authors: Seongon Jang, Dongwon Ka, Hyunsook Jung, Min-Kun Kim, Heesoo Jung, Youngho Jin
• Format: Article
• Language: English
• Published: MDPI AG 2020-07-01
• Series: Materials
• Subjects: Zr(OH)₄/GO nanocomposite; graphene oxide; degradation; nerve agent; soman (GD); humidity
• Online Access: https://www.mdpi.com/1996-1944/13/13/2954

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)₄nanocomposite. 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)₄for the soman (GD) degradation, such as surface hydroxyl groups are almost available even in high-humidity environments.