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Updated: Jun 9, 2026
07:23
Fabrication of Thin Film Silver/Silver Chloride Electrodes with Finely Controlled Single Layer Silver Chloride
Published on: July 1, 2020
Characterization of home-made silver sulphide based iodide selective electrode
A Rajbhandari Nyachhyon1, A P Yadav, K Manandhar
1Central Department of Chemistry, Tribhuvan University, Kirtipur, Kathmandu, Nepal. armila3@yahoo.com
Talanta
|August 31, 2010
Summary
This study developed silver sulfide/silver iodide ion-selective electrodes (ISEs) with varying compositions. The 1:1, 2:1, and 9:1 ratio ISEs exhibited Nernstian responses for iodide detection.
Area of Science:
- Electrochemistry
- Materials Science
- Analytical Chemistry
Background:
- Ion-selective electrodes (ISEs) are crucial for chemical analysis.
- Silver sulfide (Ag2S) and silver iodide (AgI) are key components in developing effective ISEs.
- Understanding the impact of Ag2S-AgI composition on ISE performance is vital.
Purpose of the Study:
- To fabricate and characterize polycrystalline silver sulfide/silver iodide ion-selective electrodes (ISEs) with different Ag2S-AgI mole ratios.
- To evaluate the electrochemical behavior and sensing properties of these novel ISEs.
- To investigate the semiconductor properties of the fabricated electrode materials.
Main Methods:
- Fabrication of ISEs with Ag2S-AgI mole ratios of 9:1, 2:1, 1:1, and 1:9.
- Characterization using X-ray diffractometry (XRD), scanning electron microscopy (SEM), and electrochemical impedance spectroscopy (EIS).
- Performance evaluation through Nernstian response analysis and Mott-Schottky analysis.
Main Results:
- XRD confirmed the presence of Ag3SI, Ag2S, and AgI crystalline phases.
- Electrode surface morphology improved with increased Ag2S content.
- ISEs with 1:1, 2:1, and 9:1 ratios showed Nernstian behavior (approx. 60 mV/decade) for iodide ions from 10(-1) to 10(-6)M.
- The 1:9 ratio ISE exhibited sub-Nernstian behavior (approx. 45 mV) up to 10(-5)M.
- EIS revealed charge transfer processes at the metal electrode and membrane-electrolyte interface.
- Mott-Schottky analysis indicated n-type semiconductor behavior with donor defect concentrations ranging from 5.1 x 10^14 to 2.4 x 10^19/cm^3.
Conclusions:
- The composition of Ag2S-AgI significantly influences the crystalline phases, surface morphology, and electrochemical performance of the ISEs.
- ISEs with higher Ag2S content demonstrate superior Nernstian response for iodide detection.
- The materials exhibit n-type semiconductor properties, relevant for understanding their charge transport mechanisms.
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