title: Green production of zero-valent iron nanoparticles using tree leaf extracts.
abstract: The interest in zero-valent iron nanoparticles has been increasing significantly since the development of a green production method in which extracts from natural products or wastes are used. However, this field of application is yet poorly studied and lacks knowledge that allows the full understanding of the production and application processes. The aim of the present work was to evaluate the viability of the utilization of several tree leaves to produce extracts which are capable of reducing iron(III) in aqueous solution to form nZVIs. The quality of the extracts was evaluated concerning their antioxidant capacity. The results show that: i) dried leaves produce extracts with higher antioxidant capacities than non-dried leaves, ii) the most favorable extraction conditions (temperature, contact time, and volume:mass ratio) were identified for each leaf, iii) with the aim of developing a green, but also low-cost, method water was chosen as solvent, iv) the extracts can be classified in three categories according to their antioxidant capacity (expressed as Fe(II) concentration): >40 mmol L(-1); 20-40 mmol L(-1); and 2-10 mmol L(-1); with oak, pomegranate and green tea leaves producing the richest extracts, and v) TEM analysis proves that nZVIs (d=10-20 nm) can be produced using the tree leaf extracts.
authors.affiliation: Requimte, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4200-072 Porto, Portugal.
authors.forename: S
authors.initials: S
authors.lastname: Machado
authors.forename: S L
authors.initials: SL
authors.lastname: Pinto
authors.forename: J P
authors.initials: JP
authors.lastname: Grosso
authors.forename: H P A
authors.initials: HP
authors.lastname: Nouws
authors.forename: J T
authors.initials: JT
authors.lastname: Albergaria
authors.forename: C
authors.initials: C
authors.lastname: Delerue-Matos
mesh_terms: D000975:Antioxidants / Q000378:metabolism; D028241:Camellia sinensis / Q000737:chemistry / Q000378:metabolism; D005591:Chemical Fractionation / Q000379:methods; D052918:Environmental Restoration and Remediation / Q000379:methods; D007501:Iron / Q000737:chemistry*; D029561:Lythraceae / Q000737:chemistry / Q000378:metabolism; D053768:Metal Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism; D029963:Quercus / Q000737:chemistry / Q000378:metabolism
chemical_list: D000975:Antioxidants; D010936:Plant Extracts; D007501:Iron