摘要
The present study was initiated to check the feasibility of using leach liquor as a precursor for the synthesis of magnetite (Fe 3 O 4 ) nanoparticles (MNPs). The leaching of iron was carried out from scrap iron using citric acid. The results show that 40 mL citric acid solution (0.5 M) was sufficient to solubilize 2 cm 2 work-piece in 7 days at 30 °C and 150 rpm. The increase in number of work-pieces decreased the leaching efficiency. The leach liquor obtained from this process was used for the synthesis of nanoparticles. Sodium borohydride (NaBH 4 ) was used as a reducing agent for co-precipitation of nanoparticles. X-ray diffraction (XRD) analysis showed the presence of Fe 3 O 4 . Transmission electron microscope (TEM) observations indicated that MNPs were elliptical or sphere shaped with an average size of 7 nm. The as synthesized MNPs were superparamagnetic in nature with 0.83506 G coercivity (Hc) and 11.51 emu/g saturation magnetization (Ms). Further, the MNPs showed peroxidase like activity. This ability of MNPs was used for the detection of phenol in the concentration range between 1 μM-200 mM.