Thin film trichloroethylene electrochemical sensor

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Thin film electrodes are crucial for electrochemical sensing applications.
• Platinum-titanium (Pt-Ti) and lead-platinum-titanium (Pb-Pt-Ti) thin films offer unique electrochemical properties.
• Developing sensitive and selective detection methods for environmental pollutants like trichloroethylene (TCE) is essential.

Purpose of the Study:

• To prepare and characterize an electrodeposited Pb-modified Pt-Ti thin film working electrode.
• To optimize the electrochemical sensing conditions for TCE detection.
• To establish the quantitative relationship between the sensing response and TCE concentration.

Main Methods:

• Sputtering deposition of Pt-Ti and Pb-Pt-Ti thin films on alumina substrates.
• Electrochemical deposition of a lead-modified Pt-Ti thin film electrode.
• Cyclic voltammetry and chronoamperometry for electrochemical measurements.
• Optimization of sensing potential and agitation rate.

Main Results:

• Optimal sensing potential identified as -2.10 V (vs. Ag/Ag+ with 0.1 M tetrabutylammonium perchlorate in acetonitrile).
• Optimal agitation rate determined to be 250 rpm, with a 90% response time of 15 seconds at room temperature.
• A linear correlation (id = 2.86CL) was established between sensing current (id) and TCE concentration (CL) from 100 to 700 ppm.
• The rate constant for cathodic reduction of TCE was determined to be 2.434 x 10^-3 cm^-1 s^-1.

Conclusions:

• The electrodeposited Pb-modified Pt-Ti thin film electrode is a promising sensor for TCE detection.
• The optimized sensing conditions provide a reliable and rapid method for quantifying TCE.
• The established linear relationship and kinetic data contribute to understanding TCE electrochemistry.