Waste‐derived nanomaterials for energy storage and water remediation: Structure–property–performance relationships
Yuvarajan Devarajan, G. M. Lionus Leo, Ravikumar Jayabal, Sasmeeta Tripathy, Nirav Gandhi, M. Madhusudhan, Amit Kumar, H. D. Raghavendra PrasadAbstract
Industrialization, urbanization, and consumer activity have sharply increased agricultural, plastic, industrial, municipal, and electronic waste, creating major environmental and resource management challenges. Converting waste into functional nanomaterials provides a sustainable path for resource recovery and fosters the development of circular‐economy technologies. This review critically analyzes links between structure, properties, and performance of waste‐derived nanomaterials for energy storage and water remediation. It clarifies how waste chemistry, synthesis methods, and nanostructure features influence electrochemical and environmental outcomes. Synthesis strategies, including pyrolysis, hydrothermal processing, chemical activation, sol–gel techniques, and green methods, are reviewed with a focus on their impact on porosity, surface area, conductivity, and catalytic activity. Waste‐derived carbon nanomaterials, metal oxides, silica structures, and hybrid nanocomposites show strong promise as electrode materials for supercapacitors, lithium‐ion batteries, sodium‐ion batteries, and metal–air batteries, as well as achieving efficiency in pollutant removal and water purification. Hierarchical porosity, surface functional groups, and hybrid architectures are shown to enhance charge storage, ion transport, catalytic reactions, and adsorption in these systems. The review examines sustainability, the benefits of the circular economy, techno‐economic barriers, scalability concerns, and environmental impacts. Finally, it clarifies future directions in AI‐assisted design, process optimization, scalable synthesis, and industrial implementation, supporting practical adoption of waste‐derived nanomaterials for sustainable energy and environmental solutions.