The mild and effective preparation of deuterated organic molecules is an active area of research due to their important applications. Herein, we report an air-stable and easy to access copper(I) complex as catalyst for the deuteration of mono-substituted alkynes. Reactions were carried out in technical solvents and in the presence of air, to obtain excellent deuterium incorporation in a range of functionalised alkynes. Full article

In this work, 3D-structured clay filters were prepared and coated with iron-doped titanium dioxide (Fe-TiO₂) using 3D printing and sol–gel soaking and calcination techniques. Three-dimensional printing was employed to mold and shape the clay filters before annealing. The coated and uncoated filters were characterized for different properties, i.e., morphology, optical properties, and crystalline structure, using field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), UV/Vis diffused reflectance spectroscopy (DRS), and X-ray diffraction (XRD). The FESEM images show uniform coatings of round-shaped Fe-TiO₂ on the tiny pore of the clay filter. The optical energy band gap of the obtained coating was around 2.8 eV, estimated by Tauc’s plot, compared with 3.2 eV of pristine anatase TiO₂. The XRD spectra data processed through XRD software revealed the coatings of TiO₂ on the filter surface with the obtained phase of anatase. The photocatalytic performance of bare and coated filters was initially tested for the degradation of indigo carmine (IC) dye and the obtained results suggested the photocatalytic degradation of IC dye by the Fe-TiO₂ clay filter compared with the bare filter. Afterward, the denitrification of nitrate NO₃ at various concentrations was performed using Fe-TiO₂-coated clay filters and analyzing the total nitrogen (TN) analysis and reduction of NO₃ to nitrite (NO₂⁻), nitrogen monoxide (NO), and nitrogen gas (N₂). The TN analysis revealed up to 81% denitrification efficiency of the 30 ppm NO₃ solution with the photocatalytic response of the Fe-TiO₂-coated filter. The results revealed that the Fe-TiO₂-coated clay filter has a high potential for denitrification applications under natural sunlight. Full article

The increase in environmental pollution, especially water pollution, has intensified the requirement for new strategies for the treatment of water sources. Furthermore, the improved properties of nano-ferrites permit their usage in wastewater treatment. In this regard, novel Mg_0.33Ni_0.33Co_0.33La_xFe_2−xO₄ nanoparticles (NPs), where 0.00≤x≤0.08, were synthesized to test their photocatalytic, antibacterial and antibiofilm activities. The structural and optical properties of the prepared NPs were investigated by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), UV-Vis spectroscopy and photoluminescence (PL) analysis. As La content increases, the bandgap energy increases, whereas the particle size decreases. The photocatalytic activity of the prepared NPs is evaluated by the degradation of methylene blue (MB) dye under sunlight irradiation. Superior activity is exhibited by Mg_0.33Ni_0.33Co_0.33La_0.01Fe_1.99O₄ NPs. The influence of catalyst dosage, pH, temperature and addition of graphene (Gr) on the photodegradation reaction was studied. Increasing the pH and temperature improved the rate of the photodegradation reaction. The antibacterial and antibiofilm activities of the NPs were assessed against Escherichia coli, Leclercia adecarboxylata, Staphylococcus aureus and Enterococcus faecium. Mg_0.33Ni_0.33Co_0.33Fe₂O₄ NPs inhibited bacterial growth. They had bacteriostatic activity on all isolates, with a greater effect on Gram-positive bacteria. All tested nano-ferrites had significant antibiofilm activities against some biofilms. Full article

Flower-like TiO₂ nanostructures were obtained by chemical oxidation of Ti foil using H₂O₂ combined with subsequent annealing. This paper offers an analysis of the phase transformation of 3D flower-like titanium dioxide nanostructures. The role of the annealing atmosphere, sample thickness, grain shape, and nanoflower size are discussed. The nanostructures were examined using SEM, XRD, and Raman spectroscopy. Due to the nature of these two processes, the morphology of these nanomaterials is complex, and is obtained through a reaction involving Ti foil and H₂O₂ at 80°C. A distinction is made between the layer composed of small grains at the substrate/oxide interface, elongated crystal-like structures, and outer spongle-like film. The annealing parameters, such as atmosphere (air or argon) and temperature (450 or 600 °C), affect phase composition. The photoelectrochemical performance of the anode based on flower-like TiO₂ has been shown. The thickness and phase composition of the anodes are factors that strongly affect the photocurrent. The multiphase heterojunctions proposed for 3D flower-like TiO₂ photoanodes in photoelectrochemical (PEC) cells suppose that the conduction band of anatase should be above rutile. The highest photoelectrochemical performance was obtained for a photoanode composed of 20–40% anatase and an associated thickness of 0.75–1.5 µm. Full article

Molten salts-assisted synthesis is widely used in the construction of high efficiency graphitic carbon nitride (g-C₃N₄) photocatalysts, and two isotypes of g-C₃N₄ have been synthesized by such method, namely poly (heptazine imide) (PHI) and poly (triazine imide) (PTI). However, the understanding of the structural changes taking place during the molten salt process and the structure–activity relationship of g-C₃N₄ polymorphs remain blurred. Herein, by regulating the treatment duration of g-C₃N₄ nanosheets (melon) in molten salts, we successfully synthesized g-C₃N₄ with phases of PHI, PHI/PTI and PTI. A continuous structural transformation induced by ions, in which melon transforms to a stable phase PTI via PHI, an intermediate state, was unveiled for the first time. In addition, results reveal that atomic configurations play a vital role in photo absorption, and charge carrier transfer and surface reaction, leading to significant differences in photocatalytic degradation. Among them, PHI with K⁺ and cyan groups modification, as well as high crystallinity, exhibits remarkable degradation efficiency, with 90% removal of tetracycline in 10 min and 80% removal of phenol in 60 min. This study sheds light on a deeper understanding for the molten salt-assisted synthesis and provides new ideas for preparing efficient organic semiconductor photocatalysts. Full article

This study aimed to investigate the pharmacological efficacy of gold nanoparticles (GNs) synthesized using a green route, employing the rhizome extract of Euphorbia wallichii (REEW) as a bioreductant and surface stabilizing agent. The GNs were characterized by a series of complementary analytical techniques including SEM-EDX, XRD, DLS, and IR spectroscopy. The reducing ability of REEW and synthesis of GNs were confirmed using UV–visible absorption spectroscopy, and the presence of spherical GNs with an fcc geometry was further confirmed through SEM and XRD analyses. The role of REEW’s extract as a stabilizing agent towards GNs was verified through FTIR and electronic absorption spectral measurement. The GC-MS analysis showed the presence of 41 different phytochemicals in REEW (chloromethyl 2-chloroundecanoate; cortisone; benzo[h]quinolone; piperidine, 2,4-dimethyl- 3,6,7-trimethoxyphenanthroindolizidine; 4-methyl-; 2-[2-quinolylmethyleneamino]ethanol, etc.), with RT values ranging from 3.10 to 27.22 min. The REEW-functionalized GNs exhibited promising antioxidant efficacy against H₂O₂ and ^*OH used as probe molecules. DPPH scavenging test showed significant EC₅₀ values of 19.47 µg/mL, 13.53 µg/mL, and 10.57 µg/mL at 30, 60, and 90 min of incubation, respectively. Thermal nociceptive mice significantly acquired analgesia in a dose-dependent manner. Moreover, pre-treatment with REEW-GNs significantly restored serum ALT, AST, ALT, T.P, and Bilirubin levels in PCM-intoxicated mice. The antidiabetic activity in alloxan-induced diabetic rabbits fell in orders of metformin > GNs 300 mg/kg b.w > GNs 200 mg/kg b.w > GNs 100 mg/kg b.w > saline at 0.1 h of drug administration. To sum up, REEW functionalized GNs have tremendous potential for curing degenerative/metabolic diseases caused as a result of oxidative stresses. Full article

Manganese has attracted significant recent attention due to its abundance, low toxicity, and versatility in catalysis. In the present study, a series of manganese (III) complexes supported by salan ligands have been synthesized and characterized, and their activity as catalysts in the hydrosilylation of carbonyl compounds was examined. While manganese (III) chloride complexes exhibited minimal catalytic efficacy without activation of silver perchlorate, manganese (III) azide complexes showed good activity in the hydrosilylation of carbonyl compounds. Under optimized reaction conditions, several types of aldehydes and ketones could be reduced with good yields and tolerance to a variety of functional groups. The possible mechanisms of silane activation and hydrosilylation were discussed in light of relevant experimental observations. Full article

Research results about the influence of BEA zeolite preliminary dealumination on the acid–base characteristics and catalytic performance of 1% Zn-BEA compositions in propane dehydrogenation with CO₂ are presented. The catalyst samples, prepared through a two-step post-synthesis procedure involving partial or complete dealumination of the BEA specimen followed by the introduction of Zn²⁺ cations into the T-positions of the zeolite framework, were characterized using XRD, XPS, MAS NMR, SEM/EDS, low-temperature N₂ ad/desorption, C₃H₈/C₃H₆ (CO₂, NH₃)-TPD, TPO-O_2, and FTIR-Py techniques. Full dealumination resulted in the development of a mesoporous structure and specific surface area (BET) with a twofold decrease in the total acidity and basicity of Zn-BEA, and the formation of Lewis acid sites and basic sites of predominantly medium strength, as well as the removal of Brønsted acid sites from the surface. In the presence of the ZnSiBEA catalyst, which had the lowest total acidity and basicity, the obtained selectivity of 86–94% and yield of 30–33% for propene (at 923 K) exceeded the values for ZnAlSiBEA and ZnAlBEA. The results of propane dehydrogenation with/without carbon dioxide showed the advantages of producing the target olefin in the presence of CO₂ using Zn-BEA catalysts. Full article

A hydrogen fuel cell is a highly promising alternative to fossil fuel sources owing to the emission of harmless byproducts. However, the operation of hydrogen fuel cells requires a constant supply of highly pure hydrogen gas. The scarcity of sustainable methods of producing such clean hydrogen hinders its global availability. In this work, a noble Au-atom-decorated glassy carbon electrode (Au/GCE) was prepared via a conventional electrodeposition technique and used to investigate the generation of hydrogen from acetic acid (AA) in a neutral electrolyte using 0.1 M KCl as the supporting electrolyte. Electrochemical impedance spectroscopy (EIS), open circuit potential measurement, cyclic voltammetry (CV), and rotating disk electrode voltammetry (RDE) were performed for the characterization and investigation of the catalytic properties. The constructed catalyst was able to produce hydrogen from acetic acid at a potential of approximately −0.2 V vs. RHE, which is much lower than a bare GCE surface. According to estimates, the Tafel slope and exchange current density are 178 mV dec⁻¹ and $7.90\times {10}^{-6}$ A cm⁻², respectively. Furthermore, it was revealed that the hydrogen evolution reaction from acetic acid has a turnover frequency (TOF) of approximately 0.11 s⁻¹. Full article

The base-free oxidation of furfural by non-noble metal systems has been challenging. Although MnO₂ emerges as a potential catalyst application in base-free conditions, its catalytic efficiency still needs to be improved. The crystalline form of MnO₂ is an important factor affecting the oxidation ability of furfural. For this reason, four crystalline forms of MnO₂ (α, β, γ, and δ-MnO₂) were selected. Their oxidation performance and surface functional groups were analyzed and compared in detail. Only δ-MnO₂ exhibited excellent activity, achieving 99.04% furfural conversion and 100% Propo._FA (Only furoic acid was detected by HPLC in the product) under base-free conditions, while the furfural conversion of α, β, and γ-MnO₂ was below 10%. Characterization by XPS, IR, O₂-TPD and other means revealed that δ-MnO₂ has the most abundant active oxygen species and surface hydroxyl groups, which are responsible for the best performance of δ-MnO₂. This work achieves the green and efficient oxidation of furfural to furoic acid over non-noble metal catalysts. Full article

The development of novel approaches to the remotion of pharmaceuticals in wastewater is a subject of concern due to their effect on living beings and the environment. Advanced oxidation processes and the use of relevant catalysts are feasible treatment alternatives that require further development. The development of suitable heterogeneous catalysts is a necessity. This work proposes the synthesis of an iron catalyst in a deep eutectic solvent (Fe-DES) composed of choline chloride and citric acid, which was physically and chemically characterized using SEM-EDS and TEM, FTIR, RAMAN, XRD and XPS. The characterisation confirmed the presence of iron in the form of hematite. Fe-DES was shown to be a multipurpose catalyst that can be applied in the removal of sulfamethoxazole as a reagent in the Fenton and electro-Fenton processes and as an activator of peroxymonosulfate (PMS) processes. After testing the catalyst with the aforementioned techniques, the best result was achieved by combining these processes in an electro-PMS, with great efficiency achieved by dual activation of the PMS with the catalyst and electric field, attaining total elimination at natural pH in 90 min. Furthermore, the degradation was confirmed by the detection of short-chain carboxylic acids (oxalic, succinic, and acetic) and reduction in toxicity values. These results confirm the suitability of Fe-DES to degrade high-priority pharmaceutical compounds. Full article

The effect of metal and support acidity on the hydroconversion of dimeric aryl ethers, used as model molecules for lignin, is still under debate, both in terms of hydrogenolysis (cleavage of the ether bond) and formation of by-products (coupling of aromatic monomers to dimers by alkylation reaction). Their role is investigated here in the conversion of three typical molecules representative of the α-O-4, β-O-4, and 4-O-5 ether linkages of lignin, respectively, benzyl phenyl ether (BPE), phenethoxybenzene (PEB), and diphenyl ether (DPE), at 503 K, under 18 bar of H₂ in decalin. Ru- and Pd-based catalysts were synthesized on non-acidic SiO₂ and on acidic HZSM5. Under these reaction conditions, the conversion of the ethers over the bare supports was observed in the presence of acidic sites; the effect decreased as the ether bond strength increased. The results also suggest that the product distribution is directly affected both by the support acidity and by the oxophilicity of Ru. Alkylated products from isomerization reactions, which are reported to be formed only over acidic sites, were also produced on the surface of the Ru nanoparticles. Full article

The aqueous basic systems NiSO₄·6H₂O/K₂S₂O₈ (pH = 14) and NiSO₄·6H₂O/KBrO₃ (pH = 11.5) were investigated for the catalytic conversion of benzyl alcohol and some para-substituted benzyl alcohols to their corresponding acids in 75–97% yields at room temperature. The active species was isolated and characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction, EDX and FT-IR techniques, and identified as comprising NiO₂ nanoparticles (NPNPs). The SEM and TEM images of the Ni peroxide samples showed a fine spherical-like aggregation of NiO₂ molecules with a nearly homogeneous partial size and confirmed the aggregation’s size to be in the range of 2–3 nm. The yields, turn over (TO) and turn over frequencies (TOF) were calculated. It was noticed that the aromatic alcohols containing para-substituted electron donation groups gave better yields than those having electron withdrawing groups. The optimum conditions for this catalytic reaction were studied using benzyl alcohol as a model. The mechanism of the catalytic conversion reaction was suggested, in which the produced NPNPs convert alcohols to acids in two steps through the formation of the corresponding aldehyde. The produced NiO because of this conversion is converted again to NPNPs by the excess of K₂S₂O₈ or KBrO₃. This catalytic cycle continues until all of the substrate is oxidized. Full article

Selective catalytic reduction (SCR) is an effective system for treating nitrogen oxides (NO_x; mainly NO), and fast SCR requires the equimolar reactants of NO and NO₂. This study focused on catalysts for oxidizing 50% of NO to NO₂. A series of catalysts composed of a variety of components, such as mesoporous mMnO₂-nCeO₂ as carrier catalysts (m:n = 9:1 and 7:3) and transition metals (e.g., Fe, Co, Ni, Cu, and Cr), were synthesized and characterized using N₂ adsorption, in situ XRD, TEM, and XPS. All samples had a mesoporous structure with pore size around 8 nm. XPS results demonstrated that addition of cerium ion increased the surface area and provided oxygen vacancy due to the formation of Ce³⁺ within the structure. NO oxidation activity was tested using a feed (205~300 ppm NO and 6% O₂) that simulated typical flue gas conditions. Doped mesoporous mMnO₂–nCeO₂ has higher NO oxidation activity than pristine mMnO₂–nCeO₂. The doped mMnO₂-nCeO₂ catalyzed 50% of NO to NO₂ at between 140 and 200 °C resulting in an equivalent amount of NO and NO₂. Among the transition metals, Cu, Ni, Co, Fe, and Cr have the highest to lowest oxidation activity, respectively. The precatalytic oxidation of NO can potentially be combined with the current SCR system without changes to existing equipment and can be applied to the exhaust gas treatment for de-NO_x. Full article

Developing efficient photocatalyst for the photoreduction of CO₂ and degradation of organic pollutants is an effective alternative to address increasingly serious energy problems and environmental pollution. Herein, the isostructural Sillén–Aurivillius oxyhalides, Bi₇Fe₂Ti₂O₁₇X (X = Cl, Br, and I; BFTOX), are fabricated for CO₂ reduction and degradation of organic pollutants for the first time. Density functional theory (DFT) calculations show that the valence band maximum (VBM) of BFTOC and BFTOB is contributed by the dispersive 2p orbitals of O-atoms, providing the narrow band gap (E_g) and possibly the stability against self-decomposition deactivation. The photocatalytic activities of BFTOX are strongly affected by the halogens (Cl, Br, and I), namely, the BFTOCl sample displays outstanding activity improvement (3.74 μmol·g⁻¹·h⁻¹) for photocatalytic performance. This is mainly attributed to the high separation of charge carriers, small optical band gap, and extended optical absorption. This work focuses on affording a reference to develop efficient and stable photocatalysts from Sillén-Aurivillius layered oxyhalide materials. Full article