High yield of nano zero-valent iron (nZVI) from carbothermal synthesis using lignin-derived substances from municipal biowaste

Nano zero-valent iron (nZVI) has been used as an effective catalyst in different reduction reactions. In this work, a synthesis procedure to obtain a carbon based materials with high nZVI content is reported. This synthesis method consists in a carbothermal reduction at 800 °C of Fe3O4 nanoparticles coated with lignin-derived biobased substances (BBS) as carbon source, which have been previously prepared from the co-precipitation method. The obtained materials were characterized by powder X-ray diffraction (XRD), Mössbauer spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and magnetization measurements. The concentration of carbon used in the synthesis process was a critical parameter for obtaining high nZVI yield. Nanomaterials with a 77% of α-Fe over the total iron and saturation magnetization (Ms) of 170 emu g−1 were obtained for the best condition.