Green synthesis and characterization of zero-valent iron nanoparticles using stinging nettle (Urtica dioica) leaf extract

For the first time, aqueous leaf extract of Urtica dioica was used as a sustainable source of reducing and capping agents to synthesize iron nanoparticles (INPs). In this regard, zero-valent INPs were produced and entrapped in a biologic coating. INPs were characterized by transmission electron microscopy (TEM), particle size analysis, Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometer, vibrating sample magnetometer, thermogravimetric analysis (TGA), and differential TGA. Based on the results, the prepared INPs were completely composed of zero-valent iron atoms without any iron oxide impurities. Nanoparticles were spherical in shape with diameters ranging from 21 nm to 71 nm with a mean particle size of 46 nm. Particles were entrapped in a biologic coating which resulted in formation of complexes ranging from 117 nm to 605 nm. High zeta potential value of these complexes (- 82.6 mV) and the presence of hydrophilic groups on the biologic coating provided a stable colloid system. Prepared INPs were non-crystalline (amorphous) having a low magnetization value of 0.14 emu/g. The prepared particles are of significant interest in a wide range of scientific and technical applications.