Molecular Exciton Engineering in Thiobarbituric Acid-Based Linear Copolymers for High-Efficiency Photocatalytic...

Area of Science:

• Materials Science
• Photocatalysis
• Environmental Chemistry

Background:

• Linear copolymers (LPs) offer potential for visible-light photocatalysis due to exposed active sites.
• Excitonic effects, influenced by electron-hole Coulomb interactions, are crucial for LP photocatalytic performance but often overlooked.

Purpose of the Study:

• To investigate and control excitonic properties in linear copolymers for enhanced photocatalytic uranium reduction.
• To fabricate novel thiobarbituric acid-based LPs and tune their performance by modifying donor units.

Main Methods:

• Fabrication of three thiobarbituric acid-based linear copolymers (TTP, BTB, NTN) using catalyst-free multicomponent reactions.
• Systematic substitution of donor units (phenyl, biphenyl, naphthyl) to tune excitonic properties.
• Experimental and theoretical calculations to analyze donor-acceptor interactions, exciton binding energy (Eb), and dipole moments.

Main Results:

• Stronger donor-acceptor interactions reduced exciton binding energy and amplified dipole moments, enhancing exciton dissociation and charge transfer.
• TTP, with a phenyl donor, exhibited optimal intramolecular charge transfer, minimum Eb (61.4 meV), and maximum dipole moment (13.15 D).
• Achieved high uranium extraction capacity (778.8 mg g⁻¹) and 99.6% photocatalytic removal efficiency from wastewater.

Conclusions:

• Molecular exciton control in linear copolymers is key to optimizing photocatalytic efficiency.
• Developed LPs demonstrate significant potential for treating uranium-contaminated wastewater.
• Findings pave the way for advanced photocatalytic solutions in environmental remediation.