Adsorption and Decomposition of Sarin on Dry and Wet Cu₂O(111) and CuO(111) Surfaces: Insight from First-Principles Calculations

Abstract

Adsorption and destruction of the nerve agent sarin (GB) on the pristine and hydroxylated/water surfaces of copper oxides have been investigated by extensive first-principles calculations, and the unsaturated Cu site in both CuO(111) and Cu2O(111) surfaces was predicted to have strong GB-adsorption ability through its bonding interaction with the phosphoryl oxygen of sarin. Decomposition of GB on the surface mainly proceeds through the fission of the P–F bond, and the predicted energy spans are 106.3 and 109.5 kJ/mol on the pristine and hydroxylated CuO(111) surfaces, respectively. In comparison with CuO(111), the pristine Cu2O(111) surface has a relatively strong binding interaction with GB, and the wet Cu2O(111) surface can effectively degrade GB under mild conditions with the energy span of 77.0 kJ/mol. The Cu2O(111) surface has more exposed and unsaturated Cu sites, compared to CuO(111), and their different electronic and surface structures are responsible for their distinct activities toward the decontamination of GB. Overall, both copper oxides may be used as the very promising protective materials to decontaminate GB, and the molecular-level knowledge about adsorption and decomposition of nerve agents (NAs) on related decontamination materials is essential for development of chemical protection strategies.