Investigations on Structural and Optical Properties of Various Modifier Oxides (MO = ZnO, CdO, BaO, and PbO) Containing Bismuth Borate Lithium Glasses

Synthesis and applications of bismuth-impregnated biochars originated from spent coffee grounds for efficient adsorption of radioactive iodine: A mechanism study

The adsorption of radioactive iodine, which is capable of presenting high mobility in aquatic ecosystems and generating undesirable health effects in humans (e.g., thyroid gland dysfunction), was comprehensively examined using pristine spent coffee ground biochar (SCGB) and bismuth-impregnated spent coffee ground biochar (Bi@SCGB) to provide valuable insights into the variations in the adsorption capacity and mechanisms after pretreatment with Bi(NO₃)₃. The greater adsorption of radioactive iodine toward Bi@SCGB (adsorption capacity (Q_e) = 253.71 μg/g) compared to that for SCGB (Q_e = 23.32 μg/g) and its reduced adsorption capability at higher pH values provide evidence that the adsorption of radioactive iodine with SCGB and Bi@SCGB is strongly influenced by the presence of bismuth materials and the electrostatic repulsion between their negatively charged surfaces and negatively charged radioactive iodine (IO₃^-). The calculated R² values for the adsorption kinetics and isotherms support that chemisorption plays a crucial role in the adsorption of radioactive iodine by SCGB and Bi@SCGB in aqueous phases. The adsorption of radioactive iodine onto SCGB was linearly correlated with the contact time (h^1/2), and the diffusion of intra-particle predominantly determined the adsorption rate of radioactive iodine onto Bi@SCGB (C_{stage II} (129.20) > C_{stage I} (42.33)). Thermodynamic studies revealed that the adsorption of radioactive iodine toward SCGB (ΔG° = -8.47 to -7.83 kJ/mol; ΔH° = -13.93 kJ/mol) occurred exothermically and that for Bi@SCGB (ΔG° = -15.90 to -13.89 kJ/mol; ΔH° = 5.88 kJ/mol) proceeded endothermically and spontaneously. The X-ray photoelectron spectroscopy (XPS) analysis of SCGB and Bi@SCGB before and after the adsorption of radioactive iodine suggest the conclusion that the change in the primary adsorption mechanism from electrostatic attraction to surface precipitation upon the impregnation of bismuth materials on the surfaces of spent coffee ground biochars is beneficial for the adsorption of radioactive iodine in aqueous phases.

Bi2O3–PbO–CdO–B2O3 glasses: competent candidates for radiation shielding

The Bi2O3–PbO–CdO–B2O3 glasses were shaped via the melt-quenching process. The XRD spectra reveal that the glasses are composed of amorphous material. Four distinct bands may be seen in the FTIR spectra at wavelengths between 400 and 600, 600–800, 800–1200, and 1200–1500 cm−1 range. This is due to a variety of bond stretching and vibration modes present in the system. A Monte Carlo simulation was used to verify the radiation shielding capabilities. The µ values grow as the amount of Bi2O3 in the manufactured glasses increases. The rise in µ values was coupled with a drop in the Δ0.5 values when the Bi2O3 concentration was increased. Additionally, the TF and RPE values were influenced by the enhancement in the µ values, with the RPE increasing from 34.61 to 44.42 percent and the TF values decreasing from 65.39 to 55.58 percent at 0.662 MeV when the Bi2O3 concentration was increased. The study showed that raising the Bi2O3 content improves the shielding capabilities. Thus, the produced glass samples, particularly BPCB25, exhibit excellent shielding capabilities, making them suitable for use in radiation shielding fields.