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Pharmaceutical contaminants are causing great attention for the public people, urgently requiring to be eliminated from the environment. Herein, commercial pharmaceutical carbamazepine was chosen as a model to be degraded by a heterogeneous Fenton system using natural pyrite as catalyst. The catalyst was characterized by X‐ray diffraction apparatus, high‐resolution transmission electron microscopy, and X‐ray photoelectron spectroscopy. The elements composition and chemical states of pyrite changed significantly after the Fenton reaction, which promoted the production of active species in the electron transfer process. The degradation efficiency of carbamazepine (2.5 mg/L) can reach 99.71% after 30 min with 0.3 g/L of pyrite and 5 mM of H2O2, respectively. The reaction system was suitable for a wide range of pH (3–9). The environmental adaptability examination of pyrite showed that humic acid (HA) had inhibitory effects on the degradation of carbamazepine. While the changes of degradation efficiency of carbamazepine were inconspicuous in the presence of NO3− and SO42−, indicating strong anti‐interference to environment common anions. Free‐radical capturers suggested that hydroxyl radical (∙OH), superoxide radical (∙O2−), and singlet oxygen (1O2) participated in the degradation of carbamazepine. This research has offered a new strategy of "treating wastes with wastes" to use pyrite to remove emerging pollutants. [ABSTRACT FROM AUTHOR]

This work focuses on utilizing the X‐ray diffraction technique as an alternative method to specialized and high‐cost techniques such as X‐ray photoelectron spectroscopy to obtain the cation distribution in magnetic nanoparticles as MFe2O4 with spinel structure synthesized by thermal decomposition. X‐ray diffraction measurements for MFe2O4 with M = Co2+ as transition cation (inverse spinel CoFe2O4) showed sensitivity to the cation distribution for octahedral and tetrahedral sites in this material with this kind of crystalline structure, being a good option for its determination. The cation distribution was obtained from the X‐ray diffraction intensity ratios for the most sensitive crystalline planes to the cations in octahedral and tetrahedral sites. Besides, the Debye–Scherrer equation and line profile analysis method from the diffraction pattern were used to determine the size distribution and the crystallite size. The size distribution obtained by X‐ray diffraction was from 15 to 18 nm, while transmission electron microscopy was found to be from 10 to 25 nm. The inversion degree x derived from X‐ray diffraction exhibits variability within the interval 0.6 < x < 0.8, not very far from that obtained by X‐ray photoelectron spectroscopy (x = 0.67). This material exhibits a saturation magnetization of 124.88 emu g−1. Consequently, the X‐ray diffraction technique opens the possibility of obtaining reliable information related to nanoparticles' morphological and chemical properties with spinel structure. [ABSTRACT FROM AUTHOR]

One of the most significant challenges the world is currently facing is wastewater treatment. A substantial volume of effluents from diverse sources releases numerous pollutants into the water. Among these contaminants, organic pollutants are particularly concerning due to the associated risk of being released into the environment, garnering significant attention. Rapid advancements in agriculture and industry on a global scale generate vast volumes of hazardous organic compounds, which eventually find their way into natural systems. Recently, the release of industrial wastewater has been increasing, due to the progress of numerous businesses. This poses a danger to humans and the environment, leading to environmental contamination. The application of carbon nanocomposites in applied nanotechnology has recently expanded due to their large surface area, substantial pore volume, low preparation cost, and environmental resilience. Expanding the use of nanomaterials in water treatment is essential, as magnetic carbon nanocomposites consistently demonstrate an efficient elimination of pollutants from water solutions. In the current study, we have highlighted the application of magnetic porous carbon nanocomposites in removing organic pollutants from wastewater. [ABSTRACT FROM AUTHOR]

In this study, we present the highly efficient and rapid synthesis of substituted dihydropyrimidinone derivatives through an ultrasound-accelerated approach. We utilize copper ferrite (CuFe2O4) magnetic nanoparticles as heterogeneous catalysts, employing the well-known Biginelli reaction, under solvent-free conditions. The impact of the solvent, catalyst amount, and catalyst type on the reaction performance is thoroughly investigated. Our method offers several notable advantages, including facile catalyst separation, catalyst reusability for up to three cycles with the minimal loss of activity, a straightforward procedure, mild reaction conditions, and impressive yields, ranging from 79% to 95%, within short reaction times of 20 to 40 min. Furthermore, in the context of fighting COVID-19, we explore the potential of substituted dihydropyrimidinone derivatives as inhibitors of three crucial SARS-CoV-2 proteins. These proteins, glycoproteins, and proteases play pivotal roles in the entry, replication, and spread of the virus. Peptides and antiviral drugs targeting these proteins hold great promise in the development of effective treatments. Through theoretical molecular docking studies, we compare the binding properties of the synthesized dihydropyrimidinone derivatives with the widely used hydroxychloroquine molecule as a reference. Our findings reveal that some of the tested molecules exhibit superior binding characteristics compared to hydroxychloroquine, while others demonstrate comparable results. These results highlight the potential of our synthesized derivatives as effective inhibitors in the fight against SARS-CoV-2. [ABSTRACT FROM AUTHOR]

Sulfonated-silica-coated cobalt ferrite (CoFe2O4) magnetic nanoparticles (MNPs-SiCoFe-SO3H) are efficient heterogeneous catalysts for the synthesis of 3,4-dihydropyrimidin-2(1H)-one and octahydroquinazoline derivatives in the absence of solvent. The effects of solvent, temperature, and catalyst amount on the reaction are investigated. The easy separation, reusability of the catalyst, simplicity of the procedure, mild reaction conditions, and good yields (68–95%) within short reaction times (15–70 min) are the advantages of this method. The catalyst can be reused up to eight times with not much loss of activity. Scanning electron microscopy images, X-ray diffraction spectra, and elemental analysis of the recycled catalyst show that the catalyst is stable after the reaction. [ABSTRACT FROM AUTHOR]

Heteropolyacids (HPAs) have been extensively investigated in view of their favorable attributes namely discrete ionic structure, high proton mobility, strong acidity, hydrothermal stability and reversible multi-electron redox behavior which renders them especially valuable in thermal and photocatalysis systems. Consequently, HPAs have found numerous appliances as catalysts for an array of selective synthetic transformations in organic synthesis. However, HPAs have detriments namely their extreme solubility in polar solvents and low specific surface area for a catalyst. To circumvent these drawbacks, many efforts have been made to support heteropoly acids on various nanomaterials. Herein, recent catalytic applications of HPA-supported on nanocatalysts are deliberated with a focus on useful synthesis and organic transformations including their use in conjunction with thermal/ microwaves and photochemical environment to accomplish the performance of some name reactions (Friedel -Crafts and Biginelli), the assembly of useful synthetic molecules (assorted heterocyclic compounds, acetalization, epoxidation, esterification and transesterification reactions and utilization of carbon dioxide) under sustainable and greener conditions including the safer remediation of recalcitrant pollutants (dyes, nitro compounds and antibiotics) and deactivation of bacterium in aqueous streams. [ABSTRACT FROM AUTHOR]

In this work, nano ferrite spinel NiFe2O4 was synthesized by sol-gel method and characterized by SEM, XRD, FT-IR, and VSM. In second step Schiff base made from salicylaldehyde and amino propyl triethoxy silane was used for modification of the synthesized nano ferrit. In the third step removal of Ni(II) was done using modified adsorbent and 95% efficiency was achieved. The removal rate was determined by atomic absorption spectroscopy. These studies showed that the Freundlich isotherm model was fitted well with adsorption data. Moreover, the pseudo-second order kinetic model was fitted very well with experimental data. The results demonstrated that NiFe2O4@SalenSi nanoadsorbent can be used for the removal and recovery of metal ions from wastewater over a number of cycles, indicating its suitability for the design of a continuous process. [ABSTRACT FROM AUTHOR]

Sulfonic acid was anchored on the surface of silica-coated cobalt ferrite core to obtain a new magnetically separable catalyst. The resultant composite was characterized by various techniques, including FT-IR, X-ray diffraction, FESEM, energy-dispersive X-ray, TEM, TGA, and vibrating sample magnetometer. The immobilized sulfonic acid was shown to be an efficient heterogeneous catalyst for the synthesis of α-aminophosphonates under solvent-free conditions at room temperature. The catalyst is readily recovered by simple magnetic decantation and can be recycled 7 times with no significant loss of catalytic activity. [ABSTRACT FROM AUTHOR]

Dihydropyrimidinone derivatives were synthesized in moderate to high yields in one-pot three-component condensation reactions from the corresponding aldehydes, 1,3-dicarbonyl compounds, and urea in the presence of catalytic amounts of imidazole functionalized on magnetic nanoparticles as an efficient, non-toxic, reusable, and easily available catalyst under solvent-free conditions at 80 °C. Compared to the classical Biginelli reaction, this new method consistently has the advantage of excellent yields, short reaction times, and methodological simplicity. Furthermore, the nanomagnetic catalyst could be readily handled and removed from the reaction mixture via application of an external magnet, allowing straightforward recovery and reuse. Graphical Abstract: [Figure not available: see fulltext.]. [ABSTRACT FROM AUTHOR]

Abstract: An efficient, selective and green procedure for the photocatalytic oxidation of primary and secondary benzylic alcohols to the corresponding aldehydes and ketones has been achieved using silica-encapsulated H3PW12O40 as a recyclable heterogeneous photocatalyst in acetonitrile under oxygen gas as the sole reoxidant of the catalyst. [Copyright &y& Elsevier]