Understanding unique orbital matching in graphene-supported single-atom sites for enhanced gas adsorption sensitivity

• Published in: Chemical physics letters 2023-11, Vol.830, p.140798, Article 140798
• Main Authors: Huang, Ze-Huai, Wei, Xiao-Lin, Cao, Jue-Xian, Zhang, Yan-Ning
• Format: Article
• Language: English
• Subjects: Charge transfer; Chemisorption; Orbital matching; Physisorption; Work function
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2023.140798

[Display omitted] •The gas adsorption mechanism of single metal atom on double-vacancy-decorated graphene was exhaustivelystudied through the unique orbital matching.•The orbital matching of CO/NO-2π* with TM-dxz,yz or H2S/H2Se lone pair with TM-dz2 determines the adsorption modes.•The charge transfer is closely related to the orbital energy difference and the local work function after substrate deformation.•We provide a useful way to guide the further design of TM-graphene materials for highly sensitive gas sensors. The understanding and prediction of the adsorption sensitivity of molecules in single-atom systems is an instructive and also challenging research topic. We here performed theoretical studies on interaction between isolated molecules and single transition-metal (TM) atoms in typical TM-N-C systems. This work demonstrates “unique orbital matching”, e.g. CO/NO-2π* and TM-dxz,yz, or lone pair orbital of H2S/H2Se and TM-dz2, in determining adsorption mode. The charge transfer between adsorbents and substrate could be well described by orbital energy difference and shows a linear relationship with after adsorption local work function. Our studies could provide instructive guidance for efficient design of sensitive materials.