Room-Temperature Methanol Gas Sensor Based on PEDOT:Tosylate Thin Films: Enhanced Sensitivity through Urea Surface...

Area of Science:

• Materials Science
• Chemical Sensing
• Polymer Science

Background:

• Conducting polymers like poly(3,4-ethylenedioxythiophene):tosylate (PEDOT:Tos) are versatile but underexplored for gas sensing.
• Chemiresistive sensors offer potential for detecting volatile organic compounds.

Purpose of the Study:

• To investigate pristine PEDOT:Tos as a room-temperature chemiresistive sensor for methanol (MeOH).
• To evaluate the impact of urea surface modification on PEDOT:Tos gas sensing performance.
• To explore the underlying sensing mechanism using computational methods.

Main Methods:

• Fabrication and characterization of pristine and urea-modified PEDOT:Tos chemiresistive sensors.
• Gas sensing measurements at room temperature with varying methanol concentrations.
• Density Functional Theory (DFT) calculations to elucidate the sensing mechanism.

Main Results:

• Pristine PEDOT:Tos detected methanol down to 5 ppm.
• Urea surface treatment increased the sensor response to 100 ppm MeOH by ~3.7 times (6% to 22%).
• The modified sensor achieved a limit of detection of 1.19 ppm, with response/recovery times of 17 min/8 h.

Conclusions:

• PEDOT:Tos is a promising material for room-temperature methanol gas sensing.
• Urea surface modification significantly enhances sensor performance and offers tunable properties.
• The material is suitable for cumulative sensing applications in environmental and industrial safety monitoring.