Synergistic integration of heterojunctions and hydrogels: Types, mechanisms, and applicsations

Heterojunctions, as semiconductor materials, possess excellent photocatalytic properties and are widely applied in fields such as disease treatment, biosensing, environmental remediation, and energy. However, heterojunctions still encounter issues of environmental sensitivity and low biocompatibility in practical applications, which limit their application in various fields. In recent years, the combination of heterojunctions with hydrogels to form hydrogel composites has been widely used in the medical field, environmental field, and biosensing field. This is because the encapsulation of heterojunctions by hydrogels can provide heterojunctions with good biocompatibility and increase their chemical stability. Heterojunction hydrogel composites can not only achieve efficient carrier separation but also enhance the adhesion and toughness of the interface. This paper focuses on the preparation and classification of heterojunction hydrogels, as well as the electron transfer pathways when different types of heterojunction hydrogels function, and evaluates different heterojunction hydrogels. In addition, the latest progress in the application of heterojunction hydrogels in antibacterial, wound healing, tumor treatment, environmental remediation, and biosensing is summarized. Finally, a deep discussion is conducted on the prospects and challenges of heterojunction hydrogels in practical applications. This review comprehensively introduces heterojunction hydrogels and aims to provide a new perspective for the development and application of heterojunction hydrogels.