Functional Green Nanomaterials for Plant-Mediated Heavy Metal Cleanup

Soil contamination with heavy metals (HMs) such as lead (Pb), cadmium (Cd), and chromium (Cr) is a global concern due to their toxicity, persistence, and bioaccumulation in the food chain. Conventional remediation techniques such as soil washing, stabilization, electrokinetic treatment, and excavation—can reduce HM levels but face major limitations, including high operational costs, intensive energy and chemical use, generation of secondary pollutants, and disruption of soil structure and fertility. These challenges hinder their large-scale or long-term application, particularly in resource-limited settings. Recent advances in green synthesis have enabled the development of sustainable nanomaterials (NMs) that offer eco-friendly and potentially more efficient alternatives. This review introduces PhytoNanoPurification, an emerging approach that integrates phytoremediation with nanotechnology to enhance HM removal from soils. Different classes of sustainable NMs, their synthesis routes, mechanisms of interaction with HMs, and their functional roles in remediation are discussed. Case studies reveal that NM–plant combinations can increase HMs uptake, stimulate plant biomass production, and improve overall soil health. Despite these benefits, challenges remain, including NMs toxicity, environmental persistence, scalability, and uncertainty regarding long-term ecological impacts. Addressing these issues will require interdisciplinary research, innovation in synthesis and application strategies, and the establishment of strong regulatory frameworks. By reducing HMs bioavailability in agricultural soils through plant–NMs synergies, this review directly advances SDG 2 (safe food production), SDG 6 (prevention of soil-to-water metal transfer), SDG 12 (green synthesis and responsible material use), and SDG 15 (restoration of terrestrial ecosystems).