A terbium(III) lanthanide-organic framework as a selective and sensitive iodide/bromide sensor in aqueous medium

Area of Science:

• Materials Science
• Chemical Sensing
• Coordination Chemistry

Background:

• Lanthanide-organic frameworks (LOFs) offer unique luminescent properties for sensing applications.
• Developing selective and sensitive sensors for environmental pollutants like iodide ions is crucial.
• Terbium(iii)-based materials are known for their characteristic luminescence, making them suitable for sensor development.

Purpose of the Study:

• To develop a potent luminescent sensor for the detection of iodide ions.
• To investigate the sensing mechanism and explore the potential for detecting other anions.
• To provide guidance for designing novel pollutant sensors.

Main Methods:

• Hydrothermal synthesis of a terbium(iii)-based lanthanide-organic framework using 5-(4-carboxyphenoxy)isophthalic acid (H3cpia).
• Characterization of the framework's structure and luminescent properties.
• Evaluation of the sensor's response to various anions, focusing on iodide ions (I-).
• Investigation of the luminescence quenching mechanism and detection of bromide ions (Br-) by adjusting excitation wavelength.

Main Results:

• A terbium(iii)-based LOF, [Tb(cpia)(H2O)2]n·nH2O (1), was successfully synthesized.
• Compound 1 demonstrated superior luminescence quenching for iodide ions with high sensitivity and selectivity.
• The sensor exhibited a real-time response to iodide ions.
• The luminescence quenching mechanism was attributed to absorption competition between the framework and iodide ions.
• The framework's ability to detect bromide ions by adjusting excitation wavelength was also demonstrated.

Conclusions:

• The developed terbium(iii)-based LOF serves as an effective luminescent sensor for iodide ions.
• The sensor exhibits high sensitivity, selectivity, and real-time detection capabilities.
• The findings provide insights into the sensing mechanism and suggest potential for detecting other pollutants like bromide ions.
• This work offers a general strategy for designing and synthesizing advanced pollutant sensors.