Zirconium hydroxide-activated carbon hybrid material for chemical warfare agents detoxification: Implication of water and temperature

Abstract

In light of the recent threat from chemical warfare agents (CWAs), the scientific community has focused extensively on developing effective and safe decontamination methodology for CWAs based on environmentally benign technology and the avoidance of corrosive and toxic chemicals. Herein, we report the decomposition of CWAs sarin and sulphur mustard on the hybrid material Zirconium hydroxide-granular activated carbon i.e. Zr(OH)₄@GAC which is synthesized by utilizing the reactive zirconium hydroxide and high surface area carbon. In-situ zirconium hydroxide was generated in the pores of GAC by varying the precursor concentration i.e. zirconium oxychloride followed by hydrolysis. The morphology, structural, and textural properties of the reactive hybrid material Zr(OH)₄@GAC were examined using several analytical techniques including powder x-ray diffraction, TGA, FT-IR, BET, SEM, EDX, and TEM. Furthermore, the degradation capability of Zr(OH)₄@GAC was evaluated in the hydrolytic abatement of CWAs sarin and sulphur mustard. Under pristine laboratory conditions, the effectiveness of reactive hybrid material Zr(OH)₄@GAC has been attributed due to a combination of defects and diverse surface hydroxyl species of Zr(OH)₄, as well as a high surface area carbon matrix. The impact of water content and temperature on CWAs degradation was also investigated by altering the water percentage from 2 to 8 % and the temperature 25 °C to 45 °C. The GC–MS/GC technique was used to observe the kinetics of in-situ degradation of CWAs over Zr(OH)₄@GAC The results indicated that the degradation process follows a first-order reaction kinetics. It is observed that higher water content along with elevated temperature enhance CWA decomposition on Zr(OH)₄@GAC; conversely, at lower temperature, it slowed down the degradation of CWAs. This significant enhancement in the decontamination capability of hybrid materials Zr(OH)₄@GAC towards CWAs was attributed to the synergistic effects of GAC (adsorption capacity) coupled with the reactive functional group of Zr(OH)_4.This strategy will pave the way for the development of self-detoxifying adsorbent material for environmental and defence purposes.