Robust Chemiresistive Behavior in Conductive Polymer/MOF Composites

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Conductive metal-organic frameworks (cMOFs) show promise for gas sensing.
• Current MOF-based sensors often suffer from limited reusability and slow recovery.
• Hybridization offers a potential solution to overcome these limitations.

Purpose of the Study:

• To develop high-performing, reusable gas sensors using a hybrid approach.
• To investigate the synergistic effects of combining cMOFs and conductive polymers (cPs).
• To elucidate the mechanism behind improved sensor performance.

Main Methods:

• Fabrication of chemiresistor devices using hybridized cMOF/cP materials.
• Systematic study of cMOFs with HHTP and HITP ligands and various metal nodes (Co, Cu, Ni).
• Analysis of sensor recovery kinetics, cycling stability, and dynamic range at room temperature.
• Mechanistic investigation using energy band alignment, sensing thermodynamics, and density functional theory (DFT) calculations.

Main Results:

• Hybridization significantly improves sensor recovery kinetics, cycling stability, and dynamic range at room temperature.
• Hole enrichment in the cMOF component enhances desorption kinetics, leading to better recovery and long-term response retention.
• DFT calculations support the proposed mechanism of enhanced sorbate-analyte interactions.
• Facile thin-film co-processing and device integration are achieved through alloying cPs and cMOFs.

Conclusions:

• Hybridizing cMOFs with cPs creates effective mixed ionic-electronic conductors for advanced gas sensors.
• The developed materials exhibit superior performance, including rapid recovery and stability at room temperature.
• This hybridization strategy offers a pathway for utilizing MOF-based materials in diverse electronic applications.