Tungsten oxide semiconductor (WO₃) modified using transition metals (Ni, Fe, and Zn) was synthesized via microwave-assisted solution combustion method. Ni, Fe, and Zn were doped in the WO₃ structure to improve the photocatalytic efficiency. The prepared powders were characterized by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy analysis to investigate products' structural and morphological properties and surface composition. The materials show a monoclinic structure of WO₃ with small shifts in the peak position for each catalyst. Reactive blue 194 (RB 194) aquatic solution was used for photodegradation experiments under UV irradiation to evaluate the photocatalytic properties. The results showed an improvement in photocatalytic activity of host structure within doping the iron and nickel, whereas adding zinc made a decline in decolorization efficiency of WO₃. The photocatalytic performance of samples is in the order of WO₃:Ni > WO₃:Fe > WO₃ > WO₃:Zn. The influences of operational parameters were evaluated for each catalyst to obtain the optimum conditions of the photocatalytic reaction.

This study reports experimental analyses of adsorption thermodynamics using the polymeric adsorbent surface, polyethersulfone (PES), with different molar ratios of ZnO nanoparticles. Fourier transform infrared (FTIR), X-ray diffraction (XRD), and field emission scanning electron microscopy (FESEM) were performed to study the adsorbent structure and morphology. FTIR results showed that both PES and ZnO nanoparticles were successfully incorporated into the nanocomposite, while the XRD analysis showed that the crystal adsorbent characteristics did not change. FESEM of the ZnO exhibits the formation of aggregates in the form of small spherical grains, and the sizes were in the range of 45–65 nm. The effects of different parameters (contact time, pH, temperature, adsorbent dosage, and diazinon concentrations) were investigated to find the optimal conditions of the prepared adsorbents. The equilibrium data for diazinon adsorption onto PES and ZnO/PES were analyzed using the Langmuir, Freundlich, Temkin, Dubinin-Radushkevich, Jovanovic, and Flory-Huggins models. Based on the values of the correlation coefficient, Langmuir and pseudo-second-order were found to be the best-fitting model. In addition, adsorption at different temperatures (288.15–303.15 K) was used to determine thermodynamic parameters such as free energy, enthalpy, and entropy changes. Finally, these results allow designing different processing units for pollution removal.

Water pollution by synthetic anionic dyes is one of the most critical ecological concerns and challenges. Therefore, there is an urgent need to find an efficient adsorbent and photocatalyst for dye removal. In the present study, we aimed to fabricate a hybrid mesoporous composite of spongy sphere-like SnO₂ and three-dimensional (3D) cubic-like MgO (SnO₂/MgO) as a promising adsorbent/photocatalyst to remove the anionic sunset yellow (SSY) dye from real wastewater at neutral pH conditions. The as-synthesized SnO₂ and MgO composite was investigated using XRD, SEM, EDX, TEM, XPS, BET, and zeta potential. The experimental study of the SSY removal using SnO₂/MgO composite was performed at different conditions, such as pH, stirring time, dose, and temperature. More than 99% of 10 mg/L SSY was effectively adsorbed from aqueous solution using 40 mg of SnO₂/MgO composite at pH 7 and a stirring time of 60 min. The SSY adsorption behavior was well fitted by pseudo-second order and the Langmuir model, indicating that the SSY was chemisorbed to the composite-active sites as a monolayer. On the other hand, photocatalytic degradation process exhibited better results in terms of speed of removal and used quantity of photocatalyst, where 20 mg of SnO₂/MgO composite can be used to remove > 99% of SSY dye within 30 min. Mechanism of SSY adsorption and photocatalytic degradation was discussed. In addition, elution experiments demonstrated that the SnO₂/MgO composite as an SSY adsorbent could be reused for nine cycles without considerable reduction in the SSY adsorption efficiency. Therefore, this work exhibited that the mesoporous SnO₂/MgO composite can be considered an effective adsorbent/photocatalyst to remove SSY dye from real industrial effluent water at neutral pH conditions.

The structural, optical, and magnetic qualities of Cd_1-xMn_xZnO₂ nanocomposites with (0.00 ≤ x ≤ 1.00) are investigated and the paramagnetic ferromagnetic transition is explained. Two series (effect of annealing and composition) were synthesized using the hydrothermal method and then annealed for 3 h at annealing temperatures (T_ann) of 400 °C or 600 °C. It is found that an increase in either x or T_ann correlates with significant change in unit cell volume (V), crystallite size (D_hkl), Debye temperature (θ_D) and energy gap (E_g). Further, the samples at x = 0.60 show a sudden change or inflection point in the behavior of these parameters is detected. Furthermore, the values of E_g and D_hkl for the x = 0.60 sample are independent of the chosen T_ann. The weight percent of oxygen increased as x increased, as well as it was higher at 600 °C than at 400 °C. The value of D_hkl at x = 0.40 was increased by increasing T_ann from 20.7 nm to 26.3 nm. Surprisingly, both series of samples exhibit weak paramagnetic properties as x increases to 0.40. However, increasing x to 0.60 yields a strong ferromagnetic signature for both series as well as unusual unsaturated magnetizations of 4.20 and 1.25 emu/g. However, with a larger further than of x above 0.60, the behavior returns to a strong paramagnetic behavior, but with a small percentage of residual hysteresis. These novel outcomes open the way for a possible mechanism for room temperature ferromagnetic (RTFM) and strongly recommend the use of Cd_1-xMn_xZnO₂ nanocomposites, for magnetic imaging, and spintronic devices.

Incorporating coumarin nuclei into other heterocyclic scaffolds such as thienopyrimidine can significantly increase the photophysical and biological efficiency. Accordingly, we describe in this manuscript the synthesis of new heterocyclic derivatives containing combined coumarin and pyrimidine nuclei to maximize the application benefit of the target compounds. All of the synthesized derivatives were thoroughly characterized using spectral analyses such as FT-IR, NMR, and mass spectroscopy. The photophysical properties of four compounds in solution were investigated, where the substitutions had a significant effect even when the molecule conjugation was not included. Although having similar luminescent cores, two analog compounds showed different emission colors, blue and green. Uncommonly, one derivative showed a blue shift after aggregation. DFT simulations showed that adding a terminal group can significantly alter the electronic structure or molecular packing which affected directly the luminescence behavior.