Functional nanomaterials via green synthesis: A sustainable approach to water treatment and environmental remediation

Water pollution and shortages are critical global challenges, and the green synthesis of nanomaterials provides a sustainable solution for water purification, targeting the removal of dyes, heavy metals, and bacteria. Utilizing agricultural waste (e.g., cladosiphon, bamboo, cane stalks), this approach offers eco-friendly, cost-effective alternatives to conventional methods. Recent advancements in green synthesis techniques have led to the development of carbon-based nanomaterials like carbon dots, quantum dots, nanofibers, nanotubes, and metal oxides such as ZnO, TiO 2 , and IONPs. A bibliometric analysis of 270 relevant articles (2015-2024) reveals a significant rise in publications, peaking at 57 articles in 2023, with India leading the field with 89 publications. CVarious methods have shown impressive pollution reduction: CNTs at 0.05 g/L removed 99.8% of Methylene Blue (MB), while TiO 2 eliminated 100% of RR250 dye in 60 min. Green-synthesized nanomaterials, like iron and silver, also demonstrate potential, with iron nanoparticles achieving 100% Cr (VI) removal and silver from Acacia ehrenbergiana reducing RhB dye by 96%. This review emphasizes the novelty of hybrid synthesis methods that combine green chemistry with traditional techniques, offering a useful solution for addressing challenges in scalability. By integrating these approaches, the potential of green-synthesized nanomaterials for large-scale water treatment is significantly enhanced. Future studies will focus on optimising these synthesis processes through AI-driven techniques and incorporating life cycle assessments (LCA) to evaluate the long-term environmental impact and commercial feasibility of these materials, ensuring their broader applicability and sustainability.