Lignin derived bio-polyhydroxyurethane with enhanced and durable photothermal performance under sunlight irradiation

Area of Science:

• Materials Science
• Renewable Energy
• Sustainable Chemistry

Background:

• Photothermal materials are crucial for energy and water solutions.
• Current materials face challenges in efficiency, stability, and sustainability.
• Lignin and CO₂ offer renewable feedstocks for advanced materials.

Purpose of the Study:

• To design and synthesize a bio-derived, sustainable photothermal material.
• To enhance photothermal conversion efficiency and material stability.
• To investigate the underlying mechanisms of photothermal enhancement.

Main Methods:

• Synthesis of lignin-derived polyhydroxyurethane (LPHU) using lignin and CO₂.
• Incorporation of phenolic lignin into polyurethane backbone to form hydroxycarbamate structures.
• Characterization of LPHU's light absorption, photothermal conversion efficiency, and stability.
• DFT calculations and quantum chemical simulations for mechanistic insights.

Main Results:

• LPHU exhibits broad-spectrum light absorption (200-2500 nm) and high photothermal conversion efficiency (85.90%).
• Surface temperature reaches 119.8 °C under simulated sunlight; 1.6 V generated with a thermoelectric generator.
• Material shows excellent UV-shielding, antioxidant properties, and retains 92% efficiency after 14 days of aging.
• π-π stacking and intramolecular charge transfer significantly enhance photothermal performance.

Conclusions:

• LPHU is a highly efficient, stable, and sustainable photothermal material derived from renewable resources.
• The material's unique structure, including hydroxycarbamate and hydrogen-bonded networks, drives its superior performance.
• This work provides a promising pathway for developing advanced photothermal materials for energy and environmental applications.