title: Nanostructured Ag-zeolite Composites as Luminescence-based Humidity Sensors.
abstract: Small silver clusters confined inside zeolite matrices have recently emerged as a novel type of highly luminescent materials. Their emission has high external quantum efficiencies (EQE) and spans the whole visible spectrum. It has been recently reported that the UV excited luminescence of partially Li-exchanged sodium Linde type A zeolites [LTA(Na)] containing luminescent silver clusters can be controlled by adjusting the water content of the zeolite. These samples showed a dynamic change in their emission color from blue to green and yellow upon an increase of the hydration level of the zeolite, showing the great potential that these materials can have as luminescence-based humidity sensors at the macro and micro scale. Here, we describe the detailed procedure to fabricate a humidity sensor prototype using silver-exchanged zeolite composites. The sensor is produced by suspending the luminescent Ag-zeolites in an aqueous solution of polyethylenimine (PEI) to subsequently deposit a film of the material onto a quartz plate. The coated plate is subjected to several hydration/dehydration cycles to show the functionality of the sensing film.
authors.affiliation: Division of Molecular Imaging and Photonics, Department of Chemistry, KU Leuven.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Coutino-Gonzalez
authors.affiliation: Division of Molecular Imaging and Photonics, Department of Chemistry, KU Leuven.
authors.forename: Wouter
authors.initials: W
authors.lastname: Baekelant
authors.affiliation: Division of Molecular Imaging and Photonics, Department of Chemistry, KU Leuven.
authors.forename: Bjorn
authors.initials: B
authors.lastname: Dieu
authors.affiliation: Centre for Surface Chemistry and Catalysis, Department of Microbial and Molecular Systems, KU Leuven.
authors.forename: Maarten B J
authors.initials: MB
authors.lastname: Roeffaers
authors.affiliation: Division of Molecular Imaging and Photonics, Department of Chemistry, KU Leuven; johan.hofkens@chem.kuleuven.be.
authors.forename: Johan
authors.initials: J
authors.lastname: Hofkens
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D006813:Humidity; D049449:Luminescence; D049329:Nanostructures; D012834:Silver; D017641:Zeolites
chemical_list: D017641:Zeolites; D012834:Silver