Herein we report the synthesis of organic selenide-based maleanilic and succinanilic acids in good yields (up to 95%). Their structural identities were elucidated by spectroscopic techniques (e.g., IR, ¹H- & ¹³C-NMR, and MS). The ADMET analysis, molecule electrostatic potential map, DFT, and frontier molecular orbital were used to study the organoselenium compounds’ pharmacokinetics, drug-likeness characteristics, geometries, and chemical and electronic properties. Moreover, a molecular docking tool was employed to investigate the organic selenides’ ability to inhibit the SARS-CoV-2 Mpro target (PDB: 7BFB). Within this context, organic selenides exhibited promising binding affinities to the SARS-CoV-2 Mpro receptor in the following order (12 > 11 > 10 > 9 > 7 > 8). Furthermore, molecular dynamics simulations were also carried out for 200 ns to evaluate the exact behavior of the most active compound (12) within the M^pro binding pocket of SARS-CoV-2 compared with its co-crystallized inhibitor (Co).

The polyacrylamide/gelatin–iron lanthanum oxide (P-G-ILO nanohybrid) was fabricated by the free radical grafting co-polymerization technique in the presence of N,N-methylenebisacrylamide (MBA) as cross linker and ammonium persulfate (APS) as initiator. The P-G-ILO nanohybrid was characterized by the various spectroscopic and microscopic techniques that provided the information regarding the crystalline behavior, surface area, and pore size. The response surface methodology was utilized for the statistical observation of diclofenac (DF) adsorption from the wastewater. The adsorption capacity (q_e, mg/g) of P-G-ILO nanohybrid was higher (254, 256, and 258 mg/g) than the ILO nanoparticle (239, 234, and 233 mg/g). The Freundlich isotherm model was the best fitted, as it gives the higher values of correlation coefficient (R² = 0.982, 0.991 and 0.981) and lower value of standard error of estimate (SEE = 6.30, 4.42 and 6.52), which suggested the multilayered adsorption of DF over the designed P-G-ILO nanohybrid and followed the pseudo second order kinetic model (PSO kinetic model) adsorption. The thermodynamic study reveals that adsorption was spontaneous and endothermic in nature and randomness onto the P-G-ILO nanohybrids surface increases after the DF adsorption. The mechanism of adsorption of DF demonstrated that the adsorption was mainly due to the electrostatic interaction, hydrogen bonding, and dipole interaction. P-G-ILO nanohybrid was reusable for up to five adsorption/desorption cycles.

Dyes are commonly used in industry, but disposing of them after use is a serious issue as many toxic dyes end up in wastewater. Our paper aims to address this problem by utilizing Zn_100−xSm_xO (where x = 0, 2.5, 5, and 10) nanoparticles as a cost-effective and easily produced photocatalyst to break down common industrial dyes such as Methylene blue (MB), Rhodamine B (RhB), and a mixture of both. We characterized the nanoparticles using various techniques such as x-ray diffraction, Fourier-transform infrared spectroscopy, x-ray Photoelectron Spectroscopy, and Transmission electron microscope. Our analysis confirmed that the Zn_100−xSm_xO nanoparticles have a single hexagonal phase and a regular shape, with a size of 50 nm. We found that the doping ratio of our fabricated material affects its absorption and energy gap, with Eg decreasing from 2.95 to 2.78 eV as the doping ratio increased. We evaluated the photocatalytic activity of the nanoparticles for the three types of dyes and found that Zn₉₅Sm₅O had an efficiency of approximately 80%. Zn₉₅Sm₅O was also able to adsorb 68% RhB and 67% MB in the MB-RhB mixture solution. Furthermore, we determined that the degradation of both dyes followed a pseudo-first-order reaction process.

Photocatalysis is considered as simple, green, and the best strategy for elimination of hazardous organic contaminants from wastewater. Herein, new broad spectrum photocatalysts based on pure and Sm-doped CuO/ZnO/CuMn₂O₄ ternary composites were simply prepared by co-precipitation approach. The X-ray diffraction results proved the formation of a composite structure. The transmission electron microscope (TEM) images displayed that most particles have a spherical shape with average mean sizes within 26–29 nm. The optical properties of both samples signified that the addition of Sm ions significantly improves the harvesting of the visible light spectrum of CuO/ZnO/CuMn₂O₄ ternary composites. The photocatalytic study confirmed that 97% of norfloxacin and 96% of methyl green pollutants were photo-degraded in the presence of the Sm-doped CuO/ZnO/CuMn₂O₄ catalyst after 50 and 40 min, respectively. The total organic carbon analysis revealed the high mineralization efficiency of the Sm-doped CuO/ZnO/CuMn₂O₄ catalyst to convert the norfloxacin and methyl green to carbon dioxide and water molecules. During three cycles, this catalyst presented a high removal efficiency for norfloxacin and methyl green contaminants. As a dielectric energy storage material, the Sm-doped CuO/ZnO/CuMn₂O₄ ternary composite has large dielectric constant values, mainly at low frequencies, with low dielectric loss compared to a pure CuO/ZnO/CuMn₂O₄ composite.

Efficient compositions for the selective detection of ethanol gas and the removal of organic contaminants were realized by codoping of (Gd, Nb) and (Gd, Mo) ions into TiO₂. TiO₂, Ti_0.96Gd_0.01Nb_0.03O₂, and Ti_0.96Gd_0.01Mo_0.03O₂ samples were prepared by a coprecipitation method. For all compositions, a crystalline anatase phase of TiO₂ was detected. Compared to pure TiO₂, the absorption edges of Ti_0.96Gd_0.01Nb_0.03O₂ and Ti_0.96Gd_0.01Mo_0.03O₂ samples were red-shifted, further broadening towards visible light. The morphological studies demonstrate that the grains of TiO₂ were more refined after (Gd, Nb) and (Gd, Mo) codoping. The photocatalytic efficiency of the Ti_0.96Gd_0.01Mo_0.03O₂ catalyst for degrading 20 mg/L reactive yellow 145, brilliant green, and amoxicillin was 98, 95, and 93% in 90 min, respectively. The reusability experiments indicate that the Ti_0.96Gd_0.01Mo_0.03O₂ catalyst had high stability during reuse. The high photocatalytic activity of the Ti_0.96Gd_0.01Mo_0.03O₂ catalyst was correlated to the broad visible-light absorption and effective separation of electron–hole pairs by Gd³⁺ and Mo⁶⁺ cations. The gas sensing characteristic is reflected by the high sensitivity of the Ti_0.96Gd_0.01Nb_0.03O₂ sensor to ethanol gas in the presence of different gases at 275 °C. The obtained results indicated that the (Gd, Mo) mixture could more effectively induce the photocatalytic properties of TiO₂ while (Gd, Nb) dopants were the best for reinforcing its sensing characteristics.