物理学报2025，Vol.74Issue(7)：65-75,11.DOI:10.7498/aps.74.20241737
Ag,Cu掺杂氧化石墨烯吸附NH3的第一性原理研究
First-principles study of NH3 adsorption on Ag-and Cu doped graphene oxide
摘要
Abstract
Graphene has attracted great attention due to its large specific surface area,high charge carrier mobility,and excellent electrical conductivity.However,the inherent structural integrity and zero bandgap characteristics of graphene limit its gas sensing properties.Consequently,researchers have embarked on exploring avenues such as doping graphene or using graphene oxide as a gas-sensitive material to design gas sensors that respond optimally to ammonia.This work,based on first-principle density functional theory,focuses on the field of ammonia gas sensors,investigating in detail the adsorption characteristics of ammonia molecules on graphene oxide(GO)and graphene oxide doped with Ag and Cu(AgGO,CuGO).By calculating parameters including charge distribution,density of states,band structures,and adsorption energy,this work delves into the influences of diverse oxygen-containing groups and metal doping on the gas sensing properties of graphene oxide.The research results show that there is a substantial charge density overlap between the density of states of hydroxyl groups in graphene oxide and NH3 molecules,indicating a clear tendency towards chemical adsorption.It is particularly noteworthy that after NH3 adsorption,the graphene oxide containing hydroxyl shows the highest charge transfer(0.078e)and adsorption energy(0.60 eV),which indicates that the adsorption efficacy of NH3 is higher,followed by carboxyl groups and epoxy groups,which mainly participate in physical adsorption.Furthermore,this work delves into the influence of metal doping on graphene oxide,demonstrating that the adsorption capability of doped graphene oxide hinges upon the synergistic influence of oxygen-containing groups and metal atoms,with Ag-doped graphene oxide showing a several-fold increase in adsorption energy.Through the analysis of density of states,it is found that Ag atoms resonate with s,p,and d orbitals of the N atom in NH3,proving the formation of a chemical bond between Ag atom and N atom.Moreover,a comparative analysis shows that Cu-doped graphene oxide(CuGO)has an increased charge transfer of about 0.020e and slightly higher adsorption energy than Ag-doped graphene oxide(AgGO)when adsorbing NH3.Intriguingly,under the same doping concentration,CuGO exhibits superior adsorption performance to NH3.It is worth noting that in graphene oxide doped with Ag or Cu,the adsorption mechanism of carboxyl and epoxy groups transforms from physical adsorption into chemical adsorption,while the hydroxyl groups maintain consistent chemical adsorption properties before and after doping.This indicates that doping with Ag or Cu atoms can significantly enhance the adsorption capability of graphene oxide to NH3.关键词
掺杂/氧化石墨烯/第一性原理/吸附Key words
doping/graphene oxide/first principle/adsorption引用本文复制引用
万煜炜,王瑞,周文权,王一平,蔡亚楠,王常..Ag,Cu掺杂氧化石墨烯吸附NH3的第一性原理研究[J].物理学报,2025,74(7):65-75,11.基金项目
国家自然科学基金(批准号:12204380,52002331)和西北农林科技大学科研启动项目(批准号:Z1090220158)资助的课题. Project supported by the National Natural Science Foundation of China(Grant Nos.12204380,52002331)and the Scientific Research Staring Foundation of Northwest A&F University,China(Grant No.Z1090220158). （批准号:12204380,52002331）
