Synthesis of Antioxidant Nano Zero-Valent Iron Using FeCl2 and Leucaena leucocephala Leaves’ Aqueous Extract and the Nanomaterial’s Potential to Promote the Adsorption of Tartrazine and Nigrosine

Synthetic dyes are commonly present in industrial wastewater and when discharged in water bodies without receiving a treatment capable of removing or destroying them, they turn into concerning water pollutants. These organic contaminants threaten living beings due to their toxicity, and some of them can even damage DNA. Consequently, in order to achieve sustainable development, it is necessary to develop eco-friendly tools that can efficiently manage this kind of pollution. In the present study the aqueous extract from the leaves of <i>Leucaena leucocephala</i> (an invasive plant species native to Mexico) was used to produce green nano zero-valent iron (nZVI). The nanomaterial was characterized (TEM, UV-vis, FTIR, SEM, EDS, XRD) and assayed regarding its antioxidant potential (DPPH test) and capacity to remediate the pollution caused by two dyes. It proved to be able to adsorb nigrosine (288.30 mg/g of nanomaterial) and tartrazine (342.50 mg/g of nanomaterial), and also displayed antioxidant activity (effective concentration to discolor 50% of the DPPH solution = 286.02 μg/mL). Therefore, the biogenic antioxidant nanoparticle proved also to be a possible nanotool to be applied to remediate water contamination caused by these synthetic dyes.