Photoluminescent copper(I) iodide alkylpyridine thin films as sensors for volatile halogenated compounds

Mahboubeh Jamshidi; Joey Bouheriche; James M Gardner

doi:10.3389/fchem.2023.1330227

Photoluminescent copper(I) iodide alkylpyridine thin films as sensors for volatile halogenated compounds

Front Chem. 2023 Dec 11:11:1330227. doi: 10.3389/fchem.2023.1330227. eCollection 2023.

Authors

Mahboubeh Jamshidi¹, Joey Bouheriche¹, James M Gardner¹

Affiliation

¹ Department of Chemistry, Division of Applied Physical Chemistry, KTH Royal Institute of Technology, Stockholm, Sweden.

Abstract

The paper presents the fabrication and characterization of [CuI(L)]_n thin films, where L represents various alkylpyridine ligands including 4-methylpyridine, 3-methylpyridine, 2-methylpyridine, 4-^tbutylpyridine, 3,4-dimethylpyridine, and 3,5-dimethylpyridine. The thin films were synthesized by exposing the corresponding ligands to CuI thin films through vapor deposition. The coordination reactions occurring on the films were investigated using PXRD and time-dependent photoluminescence spectroscopy, and a comparison was made between the structures of the thin films and the corresponding powder phases. The films showed primarly blue emission (λ_em = 457-515 nm) and polymeric structures with excited state lifetimes ranging from 0.6 to 5.5 μs. Significantly, the studied compounds exhibited fast reversible luminescence quenching when exposed to vapors of dichloromethane and dibromomethane (15 and 30 min respectively), and the luminescence was restored upon re-exposure to the alkylpyridine ligand (after 20 min). These findings indicate that these thin films hold promise for applications as sensors (with sensitive and reversible detection capability) for volatile halogen-based compounds (VHC).

Keywords: N-donor ligand; copper(I) iodide; sensor; thin film; time-dependent photoluminescence.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. The Swedish Energy Agency (Energimyngidgheten) supported this research through a research grant. The fund were used to purchase chemicals and pay the salary of the individuals involved in this article. The Swedish government also funded this research through the strategic research area STandUP for ENERGY and helped pay for JG’s efforts in the article.