This work describes the process of synthesizing magnesia (MgO) nanomaterials through ultrasonic electrodeposition, followed by an examination of their ability and mechanism to remove Pb(II) from industrial soil at 100, 150, and 200 W ultrasonic powers. Nanomaterials were examined for their surface shape and phase composition using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffractometry (XRD). The capability of magnesia nanomaterials to adsorb Pb(II) improved greatly when operated at 150 W, attaining a maximal 68.94 mg/g value. Adsorption of Pb(II) onto magnesia nanomaterial surfaces was examined by utilizing the pseudo-second-order kinetic and Langmuir models. The nanomaterials exhibited significant features of both chemical and monolayer adsorptions for Pb(II) as a result of the intense chemical interactions between the atoms of the magnesia nanomaterials’ surface and Pb(II), as shown by Fourier transform infrared (FTIR) analysis. At 30 °C, the magnesia nanomaterial exhibited the highest adsorption capacity for Pb(II), suggesting that temperature played a significant role in this capacity. Furthermore, the Langmuir model produced a correlation coefficient greater than 0.99, indicating an excellent fit for the adsorption behavior of magnesia towards Pb(II). The findings suggest that ultrasonic power significantly impacts the adsorption characteristics of magnesia nanoparticles synthesized via ultrasonic electrodeposition. Specifically, ultrasonic power of 150 W yields the most efficient adsorption characteristics. Moreover, the 150 W-fabricated magnesia materials demonstrated exceptional pH compatibility.

Y₂O₃-coated MgO: Ce⁺³ particles with different precipitants were prepared by the co-precipitation method; the phase and morphology of the sample were characterized by XRD, TEM, and DTA-TG, and the apparent activation energy of the coated particles was studied by thermal analysis kinetics. The results showed that the precursors synthesized by single-phase and multi-phase precipitants were calcined at 1000 °C for 1.5 h to obtain Y₂O₃-coated MgO: Ce⁺³ particles with coating thicknesses of about 2.5 nm and 5 nm. The apparent activation energies of the precursor phase change in three stages were calculated using the Doyle–Ozawa method and the Kissinger method. The average values for single-phase samples were 95.61, 74.90, and 275.27 kJ/mol, while those for multi-phase samples were 74.90, 56.06, and 240.14 kJ/mol. The activation energies for the grain growth of the two samples were 30.56 kJ/mol and 26.27 kJ/mol. Due to the differences in activation energies at each reaction stage, the reason for the influence on the thickness of the coating layer of the two precipitants is that the smaller the activation energy, the lower the required synthesis energy. An increase in coating thickness indicates an improvement in the surface activity of the coated particles. Moreover, the luminescence intensity of the composite sample is significantly higher than that of the single-phase sample, and the luminescence performance is optimal when the Ce⁺³ ion in the composite sample is 0.3 mol%.

The Journal retracts the article “Adsorption capability and mechanism of MgO nanomaterials synthesized by ultrasonic electrodeposition for Pb(II)”