Schiff-base crosslinked photothermal cellulose aerogels with architectural design for synergistic hydrophobicity, photothermal deicing and solar-thermal-electric generation.

Abstract

The efficient utilization of solar energy using renewable and biodegradable biomass-derived materials is widely regarded as a sustainable approach to mitigate the global energy crisis and reduce environmental pollution from fossil fuel consumption. Developing mechanically robust and multifunctional photothermal materials from green feedstocks is therefore of significant interest to sustainable chemistry and engineering. Herein, an architecturally inspired cellulose-based aerogel with enhanced mechanical strength, hydrophobicity, and photothermal performance was fabricated. Oxidized microcrystalline cellulose and chitosan are covalently crosslinked via dynamic imine bonds, while 3-aminopropyltriethoxysilane (APTES) -functionalized MXene was incorporated to impart efficient photothermal functionality, followed by methyltrimethoxysilane modification to improve water resistance. Directional freezing generates a vertically aligned porous architecture, enabling effective load-bearing and structural stability. The resulting aerogel exhibited high compressive strength (0.55 MPa at 21% strain;1.43 MPa at 80% strain), high hydrophobicity (water contact angle of 146.7°), and effective photothermal conversion performance, with the surface temperature rising to 74 °C under simulated solar irradiation (100 mW·cm-2). These properties enable efficient photothermal deicing for outdoor applications. Moreover, when integrated with a thermoelectric generator, the aerogel achieves solar-thermal-electric energy conversion with a maximum output power density of 1.33 W·m-2 under 150 mW·cm-2 illumination, demonstrating a sustainable strategy for clean energy applications.