Hydrogel-based nanocomposites for enhanced environmental remediation

Nanocomposites based on hydrogels have garnered significant attention as a class of advanced materials well-suited for environmental remediation applications due to their distinctive architecture, composition, and functionalities. By integrating nanoparticles into these hydrophilic three-dimensional polymer networks, mechanical strength can be enhanced to match that of composite materials, and their adsorption and catalytic properties may yield robust multifunctional products. With their high porosity, well-developed swelling capacity, and adjustable physicochemical characteristics, aqua/gels serve as an excellent means for capturing and degrading pollutants, such as heavy metals, dyes, pharmaceuticals, and microplastics, from wastewater streams. Matrices made of natural or synthetic polymers (such as chitosan, alginate, and polyacrylic acid) that incorporate nanomaterials such as TiO 2 , Cr 2 O 3, ZnO, PbO, CuS, CdS, ZnS, and GO, etc., function as selective adsorbents with photocatalytic degradation capabilities. This review discusses recent progress in the design and synthesis of hydrogel-based nanocomposites for environmental remediation, focusing on ion exchange, adsorption, and redox mechanisms, while considering their sensitivity to pH, temperature, and ionic strength. The paper also addresses biodegradability and sustainability features in hydrogel systems for environmental applications. Hydrogel-based nanocomposites offer a green and effective solution to reduce environmental pollution in water treatment. • High ability to adsorb organic pollutants and heavy metals. • Porosity and swelling can be adjusted for specific pollutant removal. • Hydrogel systems for biodegradable and eco-friendly nanocomposite materials. • The mechanical strength and stability of hydrogels are improved by nanoparticle reinforcement. • Reusability and efficient regeneration for long-term water treatment.