Energy Barrier Modulation vs Kinetic Acceleration: Tailoring WO₃ Nanofibers for Trace-Level Mustard Gas Simulant...

Area of Science:

• Materials Science
• Chemical Sensing
• Nanotechnology

Background:

• Effective detection of chemical warfare agents (CWAs) like sulfur mustard is critical for safety.
• Sulfur mustard simulants, such as 2-chloroethyl ethyl sulfide (2-CEES), are used to develop detection methods.

Purpose of the Study:

• To enhance the sensing performance of tungsten oxide (WO3) nanofibers for 2-CEES detection.
• To investigate the effects of silver (Ag) decoration and strontium (Sr) doping on WO3 nanofibers.

Main Methods:

• Defect engineering of WO3 nanofibers using Ag decoration and Sr doping.
• Gas sensing experiments to detect 2-CEES.
• Analysis of sensing mechanisms using energy barrier analysis, rate constant/activation energy correlation, and DFT calculations.

Main Results:

• Ag-decorated WO3 (AW2) and Sr-doped WO3 (SW4) nanofibers achieved experimental detection of 2-CEES at 100 ppb.
• SW4 nanofibers showed a theoretical detection limit of 55 ppb.
• Ag decoration enhanced sensing via a larger change in effective barrier height; Sr doping improved performance through oxygen vacancies, faster kinetics, and stronger adsorption.

Conclusions:

• AW2 and SW4 nanofibers demonstrate promising capabilities for trace-level 2-CEES detection.
• The study provides mechanistic insights into defect engineering for advanced metal oxide gas sensors.
• This research guides the rational design of novel gas sensing materials.