Sustainable Nanocellulose‐Based Materials for Environmental Remediation: Structure–Function Relationships and Applications

ABSTRACT Environmental pollution across water, air, and soil systems poses escalating threats to human health and ecosystem stability, driven by heavy metals, persistent organic pollutants, particulate matter (PM), bioaerosols, and toxic gases. Conventional remediation technologies often suffer from limited selectivity, insufficient efficiency, and the risk of secondary pollution. In this context, nanocellulose‐based materials, including cellulose nanofibrils (CNFs), cellulose nanocrystals (CNCs), and bacterial cellulose (BC), have emerged as sustainable and versatile platforms for environmental remediation. Benefiting from their nanoscale architectures, high specific surface area, tunable porosity, and abundant surface functional groups, these materials enable multiple pollutant removal pathways, such as physical interception, electrostatic adsorption, chemical complexation, catalytic degradation, and antimicrobial inactivation. This review systematically summarizes the structural features and surface chemistries of nanocellulose and critically assesses their performance across key remediation domains, including water purification, air filtration, and soil decontamination. The underlying mechanisms for removing PM, colloids, dissolved organic and inorganic contaminants, microorganisms, and gaseous pollutants are discussed with an emphasis on structure–property–performance relationships. Finally, we highlight major challenges in scalability, long‐term operational stability, selective remediation under complex environmental conditions, and system‐level integration, and outline future directions toward sustainable, multifunctional, and practically deployable nanocellulose‐enabled remediation technologies.