Theoretical Investigations On The Controllable Adsorption Of Sarin By Metal Or Metallic Oxides Doped CNTs

In recent years,with the development of the chemical industry,the number and types of hazardous chemicals have increased day by day.At the same time,chemical warfare agents have also developed accordingly.Chemical warfare agents can directly injure soldiers in war and have a profound impact on the environment and human health.Therefore,more and more researchers began to devote themselves to the studies of adsorption,removal,detection and degradation of chemical warfare agents.In this paper,the adsorption and detection properties of modified carbon nanotubes(CNT)for nerve agent-sarin molecules were investigated.The main findings are as follows:(1)The adsorption of sarin molecules on carbon nanotubes doped with transition metal oxides was investigated.It was found that copper oxide-doped CNT(Cu O₂/CNT)show excellent adsorption and detection performance for sarin molecule.At the same time,in order to achieve green chemistry and sustainable development strategies,the external electric field is applied to control the capture and release of sarin molecule,so as to realize the recycling of the adsorption material.The computational results show that when introducing a negative electric field,the adsorption capacity of the adsorbent for sarin molecule is weakened.As the electric field strength increases,the adsorption capacity of the substrate material for sarin molecules becomes weaker and weaker.Furthermore,when the applied negative electric field is strong enough,sarin molecule desorbs from the substrate,and the recycling of the substrate is realized.And our research found that the optical properties of the substrate changed significantly after the adsorption of sarin molecule.Accordingly,Cu O₂/CNT may become a potential sensor material for sarin molecule.In addition,in order to evaluate the application potential of Cu O₂/CNT as a sarin scavenger,we calculated the competitive adsorption of H₂O,N₂ and CO₂on Cu O₂/CNT.The results show that the adsorption selectivity of the substrate material for sarin molecule is much higher than that of the other three gas molecules,which make the Cu O₂/CNT become an ideal choice for the elimination of sarin gas in the atmosphere.(2)Since transition metal doped CNT has a large binding energy,we also studied the adsorption properties for sarin molecules taking Fe-CNT as an example.Dynamic simulation results show that the Fe-CNT is stable enough,which provides an excellent prerequisite for the adsorption of sarin molecule.Meanwhile,Fe-CNT also has good adsorption and detection performance for sarin molecule.Similarly,when a negative electric field is applied to the system,the interaction between the sarin molecule and the substrate material is weakened,and when the electric field reaches strong enough,the sarin molecule is released from the Fe-CNT.Moreover,because the optical properties of the substrate changed significantly after adsorption of sarin molecule,Fe-CNT could also be used as the material for sarin detection.In addition,to further understand the scavenging potential of Fe-CNT for sarin molecule,we also investigated the adsorption capacity of Fe-CNT for CO₂,N₂ and H₂O in the air.The results prove that Fe-CNT has good adsorption selectivity for sarin molecules.