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

Metal paddlewheels as sensors for detection of SO₂ gas: a DFT study

Jakkapan Sirijaraensre

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

E-mail: fscijkp@ku.ac.th

Received: 11 October 2021  Accepted: 8 December 2021

Abstract:

The sensing properties of the paddlewheel-type metal dimer (M-BTC: M = Fe, Ni, Cu, Zn, and Pd) toward SO₂ gas were theoretically investigated using density functional theory (DFT) at the M06-L level of theory. Single-point calculations were carried at the M06 functional to correct the energetic properties and HOMO–LUMO energy gap. The O-bound adsorption complex of SO₂ on the metal center of paddlewheels is found to be thermodynamically favorable than the S-bound ones. The trend of adsorption energy of SO₂ on the metal center is in the order Pd-BTC < Cu-BTC < Ni-BTC < Zn-BTC < Fe-BTC. Among these five paddlewheels, the Ni-BTC and Zn-BTC paddlewheels are highly sensitive toward SO₂ gas as compared to the other systems. The density of states reveals that the adsorption process significantly reduces the LUMO of the system to lower energies, enhancing the conductivity of the system. From DFT results, the energy gap of Ni-BTC and Zn-BTC is significantly reduced by 18.0 and 41.0% after the adsorption of SO₂ on the metal center. These results suggest the great potential of Ni-, and Zn-BTC paddlewheels as SO₂ sensors.

Graphical abstract

Keywords: DFT calculations; SO2 adsorption; Sensor; Metal paddlewheel

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-021-02015-w

Chemical Papers 76 (4) 2307–2315 (2022)