Topics in Catalysis最新文献

Advanced wound healing materials have drawn significant attention from researchers due to their ability to accelerate wound healing and reduce bacterial infections. This study describes the preparation and characterization of a novel wound-healing film. The film was prepared using a solvent casting method, incorporating copper ferrite nanoparticles (CuFe₂O₄ NPs) for antibacterial activity, gelatin (GLT) as the main polymer matrix, and Aloe vera extract for its well-known wound-healing properties. Using Eucalyptus camaldulensis leaves as a capping agent, CuFe₂O₄ NPs were synthesized and characterized using transmission electron microscopy (TEM) and X-ray diffractometer (XRD). The potential of the GLT/Aloe vera extract nanocomposite (NCP) film to maintain an ideal wound environment was evaluated by examining its physicochemical properties, including porosity, water vapour transmission rate (WVTR), and water absorption capacity (WAC). Water contact angle (WCA) analysis, crucial for understanding the film’s interaction with wound fluids, revealed that all the films were hydrophilic, with the GLT/Aloe vera extract NCP film having a pH of approximately 5. Surface roughness was assessed using atomic force microscopy (AFM), which showed that the NCP film had the highest roughness. The incorporation of Aloe vera and CuFe₂O₄ NPs into the GLT matrix enhanced antibacterial efficacy against Escherichia coli, potentially preventing infections and promoting faster wound healing. Furthermore, MTT assay results demonstrated maximum cell viability and growth after three days of incubation, confirming the biocompatibility of the NCP films. Overall, the findings suggests that this study contributes the development of a promising wound healing material with potential for improved therapeutic outcomes.

These days, as development advances, pollution also rises. Organic contaminants from the chemical and agricultural sectors are discharged directly into water sources, damaging aquatic ecosystems; pesticides adversely affect the environment and create numerous challenges in our lives. Therefore, innovative and efficient solutions must be created to mitigate or eliminate the negative impact of the agricultural carbofuran pesticide component on the environment due to its contamination of aquatic bodies. Extensive research has been done looking at the possibility of using a photocatalyst to degrade organic and inorganic contaminants. g-C₃N₄ Because of their cheap cost, ease of manufacture, high stability, and unique physicochemical features, nano-composites have become an increasingly popular issue in the area of material science. It is a polymeric material composed of carbon, nitrogen. Carbon nitrides possess distinctive semiconducting properties and demonstrate remarkable catalytic activity across various processes; the catalytic efficacy of g-C₃N₄ can be enhanced through doping with transition metals like La₂O₃ and V₂O₅, attributable to the semiconducting nature of carbon nitrides. The V₂O₅-doped graphitic carbon nitride photocatalysts demonstrate improved visible-light photo-catalytic action, essential for the mineralization of carbofuran. The synthesized material was evaluated using XRD, TGA, FT-IR, FE-SEM, and UV-DRS. The band gap of synthesized material was also done us UV–VIS-NIR spectroscopy. Indeed, under visible light for 120 min the degradation was more than 80% using ternary nanocomposite. Markedly, the ternary nanocomposite shows a higher efficiency than the pure g-C₃N₄.

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Metal support interaction (MSI) and oxygen vacancies have a significant impact on the performance of the Ni catalyst for dry reforming of methane (DRM) reaction. In this paper, the synergistic effect between chelating agents and dielectric barrier discharge (DBD) technology was systematically investigated by adding different chelating agents and combining with DBD during the catalyst preparation process. The introduction of the chelating agents improved the dispersion of Ni species exposing more active sites to participate in the reaction. On this basis, DBD technology significantly increased the number of oxygen vacancies on the catalyst surface while further strengthening the MSI by reducing the size of Ni nanoparticles. Notably, ethylene glycol and DBD demonstrated excellent synergistic effects in promoting the activity, stability, and carbon resistance of Ni catalysts, which could be related to the relative content of NiAl₂O₄ in catalysts. This research makes a substantial contribution to enhancing the reactivity of DRM catalyst by using chelating agents and DBD to alter the MSI and increase the number of oxygen vacancies.

Naked eye optical chemosensors have gained considerable attraction by researchers due to their low cost, selectivity, sensitivity and rapid on the spot detection properties. In this work, a Schiff base “4-(4-(dimethylamino)benzylidene)amino-1,5-dimethyl-2-phenyl-3H-pyrazol-3-one” (DMAB-AAP) was studied for its visual sensing properties to detect heavy metals ions however, it shows discriminating color changes from colorless to lemon yellow and greenish yellow for ferrous (Fe²⁺) and lanthanum (La³⁺) ions, which is consistent to red shift from 362 nm to 421 nm and 438 nm having limit of detection (:8.201times:{10}^{-7}) M and (:4.911times:{10}^{-7}) M, respectively, in the UV–Vis. absorption spectrum of DMAB-AAP. Moreover, stoichiometric binding of DMAB-AAP with Fe²⁺ and La³⁺ was found to be in 1:1 ratio. The LOD of DMAB-AAP for ferrous ions is significantly lower than WHO tolerable limits (5µM) in drinking water. Importantly, as no other Schiff base has been reported for colorimetric sensing of lanthanum, therefore, the LOD of DMAB-AAP for lanthanum ions is found comparable with various electrochemical methods.

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Using Murraya koenigii plant extract, this work reports the environmentally friendly synthesis of nickel oxide (NiO) and nickel ferrite (Ni/Fe) nanoparticles (NPs), which were used to remove hazardous colors like methylene blue (MB) and Congo red (CR) from wastewater streams. Numerous methods, including scanning electron microscopy (SEM), XRD, energy dispersive X-ray spectroscopy (EDX), FTIR, and UV–visible spectroscopy, were used to analyze NiO and Ni/Fe NPs. SEM micrographs of NiO NPs revealed irregular crystalline structure while Ni/Fe NPs showed spherical shape. The average diameter of the NiO NPs and Ni/Fe was 36.46 nm and 15.98 nm respectively as revealed in XRD data. Three different methods have been used here to find the antioxidant potential of the synthesized NPs. Biofilm inhibition activity against Escherichia coli and Staphylococcus aureus bacteria was checked for synthesized NPs which was found to be good. The anti-thrombolytic activity was performed on human blood to find the role of Ni/Fe NPs and NiO NPs as thrombolytics which was found moderate. In every activity checked, bimetallic Ni/Fe NPs showed better potential as compared to monometallic NiO NPs.

The oxidation of sulfur-containing amino acids, particularly methionine and cysteine, is central to numerous biological processes and is associated with oxidative stress, neurodegenerative diseases such as Parkinson’s and Alzheimer’s, and aging. Methionine sulfoxide reductase (Msr) plays a key role in mitigating oxidative damage by reversing methionine oxidation. This review examines the oxidation of sulfur-containing amino acids and peptides by iron complexes, focusing on their mechanistic pathways via electron transfer or oxygen atom transfer. Kinetic and mechanistic studies highlight the reactivity of methionine, cysteine, and methionine peptides with these oxidants. Density functional theory (DFT) calculations provide insights into the geometry and electronic transitions of metal-salen and oxometal-salen complexes. Electrochemical studies, using differential pulse and cyclic voltammetry, reveal the electrocatalytic properties of L-cysteine, L-methionine, and methionine peptides, demonstrating high sensitivity, low detection limits, and stability. Additionally, the antibacterial activity of Fe(III)-salen complexes is evaluated, identifying minimum inhibitory concentrations against bacterial pathogens. This comprehensive review elucidates the intricate oxidation mechanisms of sulfur amino acids and their relevance in redox chemistry, with implications for biomedical applications.

Crystalline MoVTe(Sb)NbO oxide catalysts have been shown to exhibit high oxidation catalytic performance in propane ammoxidation. However, the roles of individual elements remain unclear. In order to elucidate these elemental roles, Nb and Te were introduced into the orthorhombic Mo₃VO_x oxide (Orth-MoVO) through post-hydrothermal treatment. Structural analysis revealed that Nb covers the surface of the Orth-MoVO crystal particles, while Te is accommodated within the hexagonal channel of the orthorhombic structure. Physicochemical characterization demonstrated that Nb enhance the structural stability of the orthorhombic phase, and the introduction of Te into amorphous Mo₃VO_x oxide through post-hydrothermal treatment facilitated crystallization from the amorphous phase to the orthorhombic structure during heat treatment. These findings provide novel insights into the roles of individual elements in Mo-V-Te(Sb)-Nb oxide catalysts.

This work employed a novel, easy, and environmentally friendly method for synthesizing platinum nanoparticles over a multi-walled carbon nanotubes (CNT_f) surface, employing thiophene (TH) as a reducing agent and stabilizer. The nanoparticle size depends on Pt concentration and TH to be employed as counter electrodes in the I⁻/I₃⁻ reduction reaction and compared with the traditional Pt counter electrode. The fabricated counter electrodes were evaluated in dye-sensitized solar cells (DSSCs). The results indicate Pt₂/CNT_f hybrid material counter electrode presents a charge transfer resistance (R_CT) of 4.20 Ω, and the photovoltaic parameters of the cell were Jsc = 11.23 (mA/cm²); V_OC = 0.781 V, and FF = 60.6, with an efficiency of 5.32%. The traditional Pt counter electrode shows an (R_CT) of 8.65 Ω, and the photovoltaic parameters of the cell were Jsc = 11.37 (mA/cm); V_OC = 0.769 V and FF = 64.5, with an efficiency of 5.94%. The Pt₂/CNT_f hybrid material performs similarly to traditional Pt counter electrodes, but the Pt₂/CNT_f hybrid presents five times less Pt concentration.

This study reports the hydrothermal synthesis, comprehensive characterization, and catalytic evaluation of zirconia nanoparticles with various phases for chemoselective reduction of α-keto esters & amides. These nanoparticles exhibited remarkable catalytic activity in highly chemoselective reduction reactions in which monoclinic zirconia NP’s show excellent efficiency, particularly in the reduction of α-keto esters and amides utilizing NaBH₄ as the reductant and methanol/ethanol as environmentally benign solvents. A significant advancement is demonstrated through the achievement of 83–99% conversions for α-hydroxy esters and α-hydroxy amides in a remarkably short time frame of 20–25 min. Furthermore, the ZrO₂ nano-catalyst demonstrates remarkable reusability, maintaining catalytic activity through five consecutive cycles without significant decline. A combination of FE-SEM, XRD, EDX-elemental mapping, FTIR, BET analysis, and Ammonia TPD techniques was employed to investigate the morphology, thermal stability, crystal structure, and surface acidity of fresh ZrO₂ NP’s. The TPD results reveal that M-ZrO₂ exhibits superior acidic properties compared to T-ZrO₂.

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