Gel-nacre nanocomposite: Integrating mechanical, conductive, and photothermal advantages synergistically under saline conditions

Hydrogel nanocomposites have been enthusiastically researched as promising candidates with cost-effectiveness and sustainability for solar steam generation and flexible electronics. Based on conductivity derived from salt ions and  superior photo-vapor conversion of photothermal nanoparticles , hydrogel nanocomposites hold great potentials for ionotronics and desalination . Here, we report a mechanically robust and multifunctional gel-nacre nanocomposite based on carbon black (CB) nanoparticles strategically embedded in gel-nacre matrix, a physical crosslinked hydrogel reinforced via freeze–thaw and salting out with microphase separation structures. The CB nanoparticles play double roles of acting as nano-crosslinks and providing photothermal conversion capability, coupling gel-nacre matrix with shrinking tendency in saline, contributing to synergistical reinforcement of mechanical performances under saline conditions. The consequent CB@gel-nacre nanocomposite achieves comprehensive mechanical advantages (large strength , high toughness, ductility, and rapid self-recoverability), excellent electrical properties (good conductivity, high sensitivity, fast strain response) as well as photothermal conversion capability. Such versatile gel-nacre nanocomposite provides new opportunities for flexible devices in various scenarios such as ionotronics and desalination.