ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Sensing properties of 2D conductive M₃(HITP)₂ MOFs toward SO₂ gas: a theoretical study

Jakkapan Sirijaraensre

Department of Chemistry, Faculty of Science, Kasetsart University, Bangkok, Thailand

E-mail: fscijkp@ku.ac.th

Received: 7 April 2023  Accepted: 8 June 2023

Abstract:

Analogous to graphene, the 2D conductive metal–organic framework as M₃(HITP)₂ exhibits remarkable properties for diverse applications. This work employed DFT calculations (M06//M06-L) to investigate the adsorption and sensitivity of six M-HITP units (M = Cr, Mn, Fe, Co, Ni, and Cu) as active sensor materials toward SO₂ gas. In the adsorption process, two modes of adsorption on the metal center, namely O-bound and S-bound configurations, were found in three systems (Cr-, Mn-, and Fe-HITPs). While the remaining systems, the adsorption of SO₂ on the metal center occurs via the SO₂ sulfur atom. Among adsorption complexes, the adsorptions on Cr-HITP MOF are characterized as chemical adsorption, in which the O-bound configuration is more stable than the S-bound configuration by 10.7 kcal/mol. The population analysis reveals that only Cr-HITP shows a significant response toward SO₂ gas after adsorption, while the remaining systems are almost insensitive. The energy gap of the substrate is changed from 0.95 to 2.06 eV, indicating the adsorption of SO₂ reduces the conductivity of Cr-HITP MOF. Therefore, Cr-HITP MOF has great potential in the application of SO₂ gas sensors.

Keywords: SO2; Sensor; 2D conductive MOF; DFT calculations; Energy gap

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-02921-1

Chemical Papers 77 (10) 6053–6068 (2023)