Structural and electronic properties of H2, CO, CH4, NO, and NH3 adsorbed onto Al12Si12 nanocages using density functional theory

Liu-Kun Li; Yan-Qiu Ma; Kang-Ning Li; Wen-Li Xie; Bin Huang

doi:10.3389/fchem.2023.1143951

Structural and electronic properties of H₂, CO, CH₄, NO, and NH₃ adsorbed onto Al₁₂Si₁₂ nanocages using density functional theory

Front Chem. 2023 Feb 16:11:1143951. doi: 10.3389/fchem.2023.1143951. eCollection 2023.

Authors

Liu-Kun Li¹, Yan-Qiu Ma¹, Kang-Ning Li¹, Wen-Li Xie², Bin Huang³

Affiliations

¹ Ningxia Key Laboratory of Intelligent Sensing for the Desert Information, School of Physics and Electronic-Electrical Engineering, Ningxia University, Yinchuan, China.
² Basic Education Department, Guangdong Ocean University, Yangjiang, China.
³ Enviromental Monitoring Site of Ningxia Ningdong Energy and Chemical Industry Base, Yinchuan, China.

Abstract

In this study, the adsorption of gases (CH₄, CO, H₂, NH₃, and NO) onto Al₁₂Si₁₂ nanocages was theoretically investigated using density functional theory. For each type of gas molecule, two different adsorption sites above the Al and Si atoms on the cluster surface were explored. We performed geometry optimization on both the pure nanocage and nanocages after gas adsorption and calculated their adsorption energies and electronic properties. The geometric structure of the complexes changed slightly following gas adsorption. We show that these adsorption processes were physical ones and observed that NO adsorbed onto Al₁₂Si₁₂ had the strongest adsorption stability. The E _g (energy band gap) value of the Al₁₂Si₁₂ nanocage was 1.38 eV, indicating that it possesses semiconductor properties. The E _g values of the complexes formed after gas adsorption were all lower than that of the pure nanocage, with the NH₃-Si complex showing the greatest decrease in E _g. Additionally, the highest occupied molecular orbital and the lowest unoccupied molecular orbital were analyzed according to Mulliken charge transfer theory. Interaction with various gases was found to remarkably decrease the E _g of the pure nanocage. The electronic properties of the nanocage were strongly affected by interaction with various gases. The E _g value of the complexes decreased due to the electron transfer between the gas molecule and the nanocage. The density of states of the gas adsorption complexes were also analyzed, and the results showed that the E _g of the complexes decreased due to changes in the 3p orbital of the Si atom. This study theoretically devised novel multifunctional nanostructures through the adsorption of various gases onto pure nanocages, and the findings indicate the promise of these structures for use in electronic devices.

Keywords: Al12Si12; electronic properties; equilibrium geometries; nanocage; stability.

Grants and funding

This work was supported by the National Natural Science Foundation of China, grant number 42167016. The Natural Science Foundation of Ningxia Province in China, grant number 2022AAC03123. The Key Research and Development Program of Ningxia Province in China, grant number 2020BEB04003, and the fifth batch of the Ningxia Youth Science and Technology Talents Project, grant number NXTJGC147.