Carbonyl chitosan-induced solarthermal healable and ultratough organohydrogel for dual-mode energy production/storage

Abstract

Non-carbonized photothermal conversion materials (PTCMs) created from polysaccharides are highly intriguing but unexplored for the lacked light-absorbing groups. Meanwhile, macromolecular PTCMs operate as single molecules enable optimal solarthermal conversion remains challenge. Herein, we employ a molecular engineering strategy to enhance chitosan's absorption by incorporating robust-light-absorbing carbonyl groups to fabricate oxidized chitosan (OCTS) with 408 % enhancements in solarthermal conversion efficiency due to full-spectrum solar absorption. Then the water-soluble OCTS is utilized to fabricate gelatin/OCTS/K₃Cit/ethylene glycol (GOKE) polyelectrolyte organohydrogel with excellent solarthermal-induced self-healing, ultrastrong mechanical and antibacterial properties. The incorporation of OCTS facilitates GOKE to harvest over 98 % full-spectrum solar absorption, 92 % solarthermal driven self-healing efficiency after five cycles, and tensile strength and toughness of 5.53 MPa and 9.81 MJ m³ attributed to Hofmeister effect strategy. Encouragingly, benefiting from OCTS's excellent solarthermal conversion and polyelectrolyte properties, GOKE is assembled into solarthermalelectric generators (STEG) and triboelectricnanogenerators (TENG), showing dual-mode electric output (50.3 mA/16.4 W m² for STEG and 37 V/16.2 mW m² for TENG). Additionally, GOKE-based flexible supercapacitors exhibit energy density of 11.3 Wh kg¹ and specific capacitance of 81.5 F g¹, capable of storing energy generated by STEG/TENG. Noteworthy, this study pioneers polysaccharide-based non-carbonized PTCMs with potential applications in clean energy production/storage.