Recent Advances in Biochar-Based Hydrogel Composites: Preparation, Aquatic Environmental Applications, and Adsorption Mechanisms

In the face of the escalating crisis of water pollution, biochar-based hydrogel composites (BCGs) have emerged as a promising material for water treatment, owing to their distinctive performance and environmental friendliness. These composites combine the high specific surface area and porous structure of biochar with the three-dimensional network of hydrogel, demonstrating superior adsorption capacities and ease of recyclability within aquatic systems. This paper provides the first overview of BCGs synthesis methods, with a particular emphasis on encapsulation and co-pyrolysis techniques. Furthermore, the environmental applications of BCGs are summarized, focusing on their efficacy and mechanisms in the removal of organic contaminants, heavy metals, and nutrients from water bodies. Our analysis underscores the pivotal role of BCGs in environmental preservation and pollution mitigation efforts, suggesting that its implementation could lead to a significant advancement in water pollution abatement strategies.