PDI-Based Organic Small Molecule Regulated by Inter/Intramolecular Interactions for Efficient Solar Vapor Generation.

Area of Science:

• Materials Science
• Photochemistry
• Environmental Engineering

Background:

• Organic small molecules are promising for solar vapor generation but face challenges like narrow absorption and low efficiency.
• Perylene diimide (PDI) derivatives offer potential due to their structural diversity and tunable properties.

Purpose of the Study:

• To design and synthesize novel PDI derivatives for efficient solar vapor generation.
• To investigate the photothermal conversion mechanisms and performance of these new materials.

Main Methods:

• Synthesis of N,N'-bis(3,4,5-trimethoxyphenyl)-3,4,9,10-perylenetetracarboxylic diimide (PDI-DTMA) with a donor-acceptor-donor configuration.
• Construction of 3D hybrid hydrogels (PPHs) using PDI-DTMA and polyvinyl alcohol.
• Experimental and theoretical calculations to analyze photothermal conversion efficiency and solar absorption.

Main Results:

• PDI-DTMA exhibits expanded absorption spectrum and enhanced nonradiative transition capability due to π-π stacking and charge transfer.
• The PPHs achieved high water evaporation rates of 3.61-10.07 kg m⁻² h⁻¹ under one sun.
• Demonstrated potential for seawater desalination and sewage treatment.

Conclusions:

• PDI-DTMA is an effective sunlight absorber for solar vapor generation.
• The developed PPHs show high efficiency and stability for solar water evaporation.
• This work advances the design of photothermal organic molecules for sustainable water treatment.