In Situ Infared Optical Fiber Sensor Monitoring Reactants and Products Changes during Photocatalytic Reaction

Area of Science:

• Photocatalysis
• Chemical Sensing
• Spectroscopy

Background:

• In situ monitoring of photocatalytic reactions is crucial for understanding reaction dynamics.
• Existing methods face challenges with apparatus complexity and limited substance applicability.
• Developing advanced sensors is key to overcoming these limitations.

Purpose of the Study:

• To develop a novel in situ infrared optical fiber sensor for monitoring photocatalytic reactions.
• To enhance the sensitivity and applicability of in situ reaction monitoring.
• To investigate the photocatalytic reaction between benzaldehyde and ethanol using the developed sensor.

Main Methods:

• Fabrication of an infrared optical fiber sensor with four tapered regions.
• Characterization of sensor sensitivity and performance.
• In situ monitoring of benzaldehyde and ethanol photocatalysis using TiO2 and UV light.
• Establishment of calibration plots and kinetic analysis of reaction progression.

Main Results:

• The developed sensor exhibited a sensitivity of 0.71 au/vol %, 70 times higher than conventional fiber sensors.
• Real-time concentrations of reactants and products were accurately determined.
• Reaction kinetics followed a first-order model, and equilibrium concentrations were determined.
• Increased UV light intensity correlated with an increased reaction rate.

Conclusions:

• The in situ infrared optical fiber sensor provides a sensitive and effective tool for real-time photocatalytic reaction monitoring.
• This technology aids in elucidating complex photocatalytic mechanisms.
• The sensor's performance demonstrates its potential for various chemical reaction studies.