Highly efficient lead removal from water by Nd(0.90)Ho(0.10)FeO(3) nanoparticles and studying their optical and magnetic properties

Ho-doped NdFeO(3) was synthesized using the citrate method. The X-ray diffraction (XRD) illustrated that Nd(0.90)Ho(0.10)FeO(3) was crystalline at the nanoscale, with a crystallite size of 39.136 nm. The field emission scanning electron microscope (FESEM) illustrated the porous nature of Nd(0.90)Ho(0.10)FeO(3), which increases the active sites to absorb the heavy metals on the sample surface. Energy-dispersive X-ray (EDX) data assures the prepared sample has the chemical formula Nd(0.90)Ho(0.10)FeO(3). The magnetic properties of Nd(0.90)Ho(0.10)FeO(3) were determined using the magnetization hysteresis loop and Faraday’s method. Many magnetic parameters of the sample have been discussed, such as the coercive field, the exchange bias (H(ex)), and the switching field distribution (SFD). Ho-doped NdFeO(3) has an antiferromagnetic (AFM) character with an effective magnetic moment of 3.903 B.M. The UV–visible light absorbance of Nd(0.90)Ho(0.10)FeO(3) is due to the transfer of electrons from the oxygen 2p state to the iron 3d state. Nd(0.90)Ho(0.10)FeO(3) nanoparticles have an optical direct transition with an energy gap E(g) = 1.106 eV. Ho-doped NdFeO(3) can adsorb many heavy metals (Co(2+), Ni(2+), Pb(2+), Cr(6+), and Cd(2+)) from water. The removal efficiency is high for Pb(2+) ions, which equals 72.39%. The Langmuir isotherm mode is the best-fit model for adsorbing the Pb(2+) ions from water.