A novel photo-regulated self-healing hydrogel based on hollow SiO₂@g-C₃N₄@TiO₂ and PVA

Self-healing hydrogels have the ability to repair themselves at the incision after being damaged and can return to their original state of morphology and performance. However, constructing a hydrogel with superior mechanical strength and tensile properties after self-healing remains a challenge. In this work, using polyvinyl alcohol, borax, chitosan, and a type of SiO₂@g-C₃N₄@TiO₂ nanoparticles as raw materials, a novel photo-regulated self-healing hydrogel was developed using a freezing-thawing method, which could achieve a synchronous increase in Young's modulus and tensile strength under visible light irradiation during the self-healing process. In addition, the doping of the SiO₂@g-C₃N₄@TiO₂ nanoparticles improved the self-healing performance of the PVA-based hydrogels. With the addition of a trace amount of SiO₂@g-C₃N₄@TiO₂ nanoparticles, the self-healing efficiency of the hydrogel increased from 26.67% to 45.67% in darkness and from 41.33% to 65.67% under visible light irradiation.