UV-visible Studies Research Articles

Molecular Copper-Anthraquinone Photocatalysts for Robust Hydrogen Production.

The development of robust and inexpensive photocatalysts for H2 production under visible light irradiation remains a significant challenge. This study presents a series of square planar copper anthraquinone complexes (R4N)CuL2 (R = ethyl, L = alizarin dianion (CuAA); R = n-butyl, L = purpurin dianion (CuPP), (2-hydroxyanthraquinone)formamide dianion (CuAHA)) as molecular photocatalysts to achieve high long-term stability in visible-light-driven H2 production. These complexes are self-sensitized by the anthraquinone ligands and serve as proton reduction photocatalysts without additional photosensitizers or catalysts. Under irradiation of blue light, complex CuAA produces H2 in a mixture of H2O/DMF with undiminished activity over 42 days, giving a turnover number exceeding 6800. Electrochemical and UV-vis studies are consistent with an EECC mechanism (E: electron transfer and C: protonation) in the catalytic cycle. The initial photochemical steps involve conversion of both anthraquinone ligands to hydroquinones. Further light-driven reductions of the hydroquinones followed by two protonation steps results in formation of H2. Dependence of the catalytic rate on the concentration of H2O suggests that either the generation of a CuII-H intermediate by protonation or heterocoupling between CuII-H and H+ to produce H2 is the turnover-limiting step in catalysis.

PHYSICOCHEMICAL AND SPECTROSCOPIC ANALYSIS OF INTERACTIONS BETWEEN ASPIRIN AND NORMAL SALINE AT DIFFERENT TEMPERATURES

The primary goal of the current investigation is to explore the molecular interactions between the aspirin (2-Acetoxybenzoic acid) and normal saline (0.9% w/v aqueous NaCl) at various concentrations (0.001–0.010) m and temperature (T= 300.15–315.15) K. To understand the various possible molecular interactions, volumetric, acoustic, conductometric and viscometric parameters were evaluated using experimental measured values of densities (ρ), ultrasonic velocities (u), specific conductance (κ), and viscosities (η). The results derived from these parameters have been examined in terms of drug–solvent and drug-drug interactions. The results of physicochemical studies indicate that aspirin exhibits strong interactional and structure–forming behaviour in normal saline. These results were well supported by UV-visible spectral studies which indicate the existence of intense aspirin–normal saline interactions in the form of modification in absorption maximum and absorption wavelength. The cyclic voltammetric studies were also performed to explore the oxidation/reduction behaviour and effect of aspirin on hemolysis. The experimental analysis of these studies provides valuable insights for better drug design, drug delivery, compatibility, potential safety, and biological relevance for the pharmaceutical and health industries.

Photon Sensitizer by Amalgamation of SrTiO3 and Dyes from Cnidoscolus Aconitifolius with Different pH Values for the Extensive Sustainability of the Dye Sensitized Solar Cell

By using the co-sensitization process, which involves combining dyes with perovskite materials, improvements in panchromatic light-harvesting and photovoltaic performance are reported for DSSC. This study aims to explore the effect of natural extract of Chaya tree spinach mixed with undoped SrTiO3 perovskite. Dyes were extracted from the leaves of Chaya tree spinach (Cnidoscolus Aconitifolius) leaves. An undoped SrTiO3 is synthesized via solid state method and mixed with TiO2 and dyes of Chaya spinach in order to fabricate solar cells. The prepared samples were characterized by structural properties by XRD and also optical properties by UV (DRS) for SrTiO3, UV-Vis and FTIR studies for the extracted dyes. The effect of the natural dye’s extracts containing chlorophyll a from Chaya tree spinach along with SrTiO3 was investigated for the performance of J-V characterization in which the cell made with SrTiO3 + natural dyes of pH maintained at 10 had shown better efficiency of about 1.691% in light with 3.4939 mA/cm2 of Jsc and 0.6023 Voc.

Tecoma stans intermediated green synthesis of copper oxide nanoparticles, its characterization, paracetamol degradation and biological activities

The main objective of the present research work is to green synthesize copper oxide nanoparticles (CuO NPs) and to study its potential against various enmities to safeguard our environment and health. Based on this approach, preparation of CuO NPs was accomplished using four different volumes (10, 25, 40, and 50 mL of leaves extract) of Tecoma stansleaves extract. Moreover, all the synthesized CuO NPs were characterized using XRD, UV–visible, FTIR, and SEM with EDS analysis. From the XRD pattern, the structures of all the synthesized CuO NPs were found to be monoclinic in phase. According to the UV–visible studies, the calculated band gap energy values for all the prepared CuO NPs were higher compared to bulk CuO, which was 1.2 eV. Further, the FTIR results showed the presence of CuO bond and SEM with EDS analysis revealed the surface morphology of CuO NPs andthe presence of elements showing the purity of synthesized CuO NPs, respectively. The optimized condition for the preparation of CuO NPs were 50 mL of leaves extract mixed with 50 mL of double distilled water (CuO4 NPs) showed a spheroidal morphology as evident from the HRTEM images. XPS analysis used to find the oxidation state of detected elements especially for copper and oxygen. The predicted BET and Langmuir surface area of CuO4 NPs were calculated to be 40.305 m2/g and 5074.12 m2/g respectively. Photocatalytic degradation of paracetamol (PCM) using CuO4 NPs was investigated, and the effect of parameters such as pH, initial concentration of PCM solution, and catalyst dosage were studied under UV light irradiation. The highest removal of 95.15 % had been achieved at 120 min under optimized reaction conditions. Additionally, CuO4 NPs also exhibited exemplary antibacterial activity against bacillus subtilis bacteria with a zone of inhibition of 26 mm. Further, in vitro cytotoxic behaviour of CuO4 NPs was estimated using A549 cancer cells by MTT assay. Thus, the green synthesis of CuO NPs using Tecoma stans leaves extract has the capacity to participate in photocatalytic and biological activities.

Green synthesis of silver nanoparticle by Hyoscyamus muticus L. extract and study of its effect on tomato infected with Meloidogyne javanica

In this study, the aqueous leaf extract of Hyoscyamus muticus L Plant leaf was prepared using three methods: maceration (MAC), microwave-assisted extraction (MAE), and ultrasonic-assisted extraction (UAE). Then, the extracts were used to synthesize silver nanoparticles (Ag NPs) in an environmentally friendly approach. The characterization of the synthesized Ag NPs was carried out by various techniques. The XRD results confirmed the successful synthesis of nano-sized Ag crystals with spherical structure. The SEM images showed the formation of Ag NPs, which were smaller than 75 nm. The UV-Vis studies showed an obvious absorption peak for Ag NPs between 400-500 nm, with a clear peak around 450 nm for all samples. The elemental analysis using the EDS technique confirmed the presence of silver in the synthesized Ag NPs. Furthermore, the effect of different concentrations of Ag NPs was investigated on hatching and second-stage juvenile (J2s) mortality of Meloidogyne javanica, under controlled conditions. The results showed that increasing concentrations of Ag NPs led to higher percentages of inhibition of egg hatching and J2s mortality. Additionally, the Ag NPs synthesized by ultrasonic-assisted extraction with lower lethal concentration were found to be more toxic to M. javanica than the extract prepared by soaking. According to the results, Ag NPs showed a stronger inhibitory effect on M. javanica egg hatching and J2s mortality compared to the total extracts and chemically synthesized Ag NPs. Also, the lowest LC50 was observed for the Ag NPs synthesized using the plant extract as: UAE > MAE (180 w) > MAE (90 w) > MAC methods. The highest inhibition of egg hatch occurred at 0.5 % v/v of Ag NPs after 72 hours and remained consistent after 120 hours.

Synthesis of zinc oxide semiconductor nanoparticles using natural extract: a systematic evaluation of cationic dye photodegradation influenced by extract concentration, catalyst dose, and pH.

This work obtained zinc oxide nanoparticles (ZnO NPs) using organic components extracted from Waltheria americana at different concentrations. ZnO materials were subsequently applied in the photodegradation of two cationic dyes, Rhodamine B (RB) and methylene blue (MB), at different doses of catalyst and pH. The crystallinity and hexagonal Wurtzite structure of ZnO were established through XRD analysis. The Zn-O bond in the ZnO NPs was confirmed in the FTIR, with the characteristic signals observed in the fingerprint region at ~ 400cm-1. SEM and TEM revealed the formation of quasi-spherical particles with an average size ranging from 2 to 12nm, depending on extract concentrations during synthesis. UV-Vis studies indicated the optical bandgap of ZnO, with values below 3eV, also dependent on extract concentration. PL analysis revealed the recombination of free excitons and defects in ZnO. Photocatalytic studies of ZnO materials demonstrated excellent degradation efficiency of RB and MB dyes, which was influenced by the extract concentration of NPs, while the degradation of MB was enhanced with a 1:1 dye-to-catalyst ratio under acidic conditions. In contrast, due to RB more complex structure, an increased ratio of 1:1 to 1:3 and acidic pH conditions improved its degradation. Green-synthesized ZnO NPs using photocatalysis techniques exhibit significant potential as eco-friendly alternatives for removing contaminants from water.

Hybrid Pd0.1Cu0.9Co2O4 nano-flakes: a novel, efficient and reusable catalyst for the one-pot heck and Suzuki couplings with simultaneous transesterification reactions under microwave irradiation.

We report the fabrication of a novel spinel-type Pd₀.₁Cu₀.₉Co₂O₄ nano-flake material designed for Mizoroki-Heck and Suzuki coupling-cum-transesterification reactions. The Pd₀.₁Cu₀.₉Co₂O₄ material was synthesized using a simple co-precipitation method, and its crystalline phase and morphology were characterized through powder XRD, UV-Vis, FESEM, and EDX studies. This material demonstrated excellent catalytic activity in Mizoroki-Heck and Suzuki cross-coupling reactions, performed in the presence of a mild base (K₂CO₃), ethanol as the solvent, and microwave irradiation under ligand-free conditions. Notably, the Heck coupling of acrylic esters proceeded concurrently with transesterification using various alcohols as solvents. The catalyst exhibited remarkable stability under reaction conditions and could be recycled and reused up to ten times while maintaining its catalytic integrity.

Synthesis, spectroscopic, computational, topology, and molecular docking studies on N,N'-(4-methyl-1,3-phenylene)bis(1-(2,4-dichlorophenyl)methanimine)

The study extensively examined N,N'-(4-methyl-1,3-phenylene)bis(1-(2,4-dichlorophenyl)methanimine) (6D). Advanced spectroscopic techniques, including IR, Raman, NMR, and UV-VIS spectroscopies, were employed to analyse the molecule. The Schiff base was ultimately confirmed using NMR spectrum analysis. The UV-VIS study revealed a notable bathochromic change in the compound, indicating their electronic transitions. By using the HOMO–LUMO bond gap the titled compound reactivity sites were identified. The compound 6D HOMO–LUMO band gap is 3.70 eV. Various wave function investigations like MESP, HOMO–LUMO, RDG, ELF, LOL, and ALIE were conducted to elucidate the distribution of electronic charge, providing valuable insights into the behaviour of molecules. The biological probability of the synthesised compound was extensively assessed using a docking study. Using MEP and HOMO–LUMO investigations, we confirm nucleophilic and electrophilic attacking sites. In the docking study, the protein Bovine cytochrome bc1 complex stigma Tellin bound (PDB ID–1PP9) was downloaded. The docking study identified the most stable minimum binding energy is –6.26 kcal/mol.

Benzyl Isothiocyanate Loaded Gelatin Nanoparticles Display Unique in Vitro Antioxidant Prospects

This present investigation focuses on the fact that nanoformulation of phytochemicals could enhance the therapeutic capacity in different physiological systems by enhancing hydrophilicity and bioavailability. In this study gelatin nano-formulation of benzyl isothiocyanate (BITC) was prepared and characterized by dynamic light scattering and UV-Visible spectrometry. Then antioxidant activity of BITC and BITC-gelatin NPs was determined in different concentrations through measuring 2,2- diphenyl-1- picrylhydrazyl (DPPH), superoxide, hydroxyl radical, nitric oxide scavenging and lipid peroxidation inhibition activities. DLS and UV-Vis study revealed the production of uniform nanosized particles and effective encapsulation of BITC respectively. The results of antioxidant assays suggested that BITC-gelatin NPs more effectively scavenged free radicals and inhibited lipid peroxidation compared to free BITC. The findings proposed that gelatin formulated BITC nanoparticles could be effective against oxidative stress related disorders.

Structural, optical, photocatalytic and thermal behaviour of (Nb, Ta) co-doped WO3 nanoparticles and its application in photocatalytic degradation of MG and RhB dyes

In this communication, eco-friendly, cost effective and facile hydrothermal route was adopted to synthesize pure WO3, Nb-doped WO3 and (Nb, Ta) co-doped WO3 nanoparticles. Phase, lattice constants, crystallite size and crystallinity have been evaluated through X-ray diffraction. The insertion of Nb and Ta ions into WO3 nanoparticles was confirmed by XPS, FTIR and EDS studies. HRTEM and SAED micrographs exhibited highly nanocrystalline nature of samples. UV–visible studies was carried out to analyse nature of band gap, band gap energy, extinction coefficient, refractive index, Urbach energy and optical conductivity of prepared samples. Optical band gap was narrowed from 2.94 to 2.49 eV and Urbach energy was extended from 0.08 to 0.35 eV through co-doping of (Nb, Ta) ions into WO3 NPs. Reduction in PL intensity revealed that electron-hole pair recombination rate was decreased with co-doping of (Nb, Ta) ions. The photo-degradation efficiency of (Nb 5 %, Ta 5 %) co-doped WO3 nanophotocatalysts was 93.12 % against MG and 90.11 % against RhB dyes. The rate constant was found to be increased from 0.0107 to 0.0203 min−1 for MG and 0.0086 to 0.0174 min−1 for RhB. Thermal results exhibited the weight loss in three phase degradation processes, and thermal stability. The results showed that (Nb 5 %, Ta 5 %) co-doped WO3 NPs is a potential candidate for practical applications in environmental remediation (organic dyes degradation).

Nitrogen and Sulfur Doped Porous Carbon Sheet with Trace Amount of Iron as Efficient Polysulfide Conversion Catalyst for High Loading Lithium-Sulfur Batteries.

The major challenges in enhancing the cycle life of lithium-sulfur (Li-S) batteries are the polysulfide (PS) shuttling and sluggish reaction kinetics (S to Li2S, Li2S to S). To alleviate the above issues use of hetero atom doped carbon as cathode host matrix is a low-cost and efficient approach as it works as a dual-functional framework for PS anchoring as well as electrocatalyst for faster redox kinetics. Here, the dual role of the Fe-containing heteroatom-doped carbon sheets (CS) in chemisorption of Li2S6 and catalyzing its faster conversion to Li2S is established through UV-Vis, XPS and CV studies. To substantiate the catalytic effect composite cathodes were prepared by encapsulating sulfur in CS which is further blended with carbon nanotubes (CNTs) to form free-standing cathode. The electrochemical performance of the three cathodes viz., S@Fe-N-CS-CNT, S@Fe-S-CS-CNT and S@Fe-NS-CS-CNT were evaluated by constructing Li-S cells. Among all, the S@Fe-NS-CS-CNT delivers a high initial discharge capacity of 1017 mAh g-1 at 0.5 C rate and sustains 751 mAh g-1 capacity after 260 cycles with a capacity retention of 73.8 %. Even at high S-loading (12 mg cm-2), it delivers an initial discharge capacity of 892 mAh g-1 and it retained 575 mAh g-1 after 200 cycles.

FABRICATION AND CHARACTERIZATION OF BISMUTH TELLURIDE THIN FILMS BY THERMAL EVAPORATION TECHNIQUE

An interest in the study of the structural and optical properties of topological insulators, led to the selection of Bismuth telluride thin films. Among the topological insulators, Bismuth telluride is one of the promising materials that exhibit applications in the field of thermoelectric power generation. The films were prepared using the thermal evaporation method under vacuum conditions of [Formula: see text] mbar on glass substrates maintained at a temperature of 120∘C. The thickness of the film samples ranges from 400 Å to 1400 Å. Pure phases of Bi2Te3 with a rhombohedral structure are confirmed using X-ray Diffraction. The crystallite size was calculated using Debye–Scherrer’s formula. Structural morphology and compositions are examined using SEM and EDAX. The UV–Vis study reflects the optical behavior of the thin film samples. The absorption spectra gives the direct and allowed transition band gap of the Bi2Te3 thin film samples for various thicknesses. The band gap decreases with the increase in the thickness of the Bi2Te3 thin films, suggesting that the material has significant absorption towards the visible spectrum. The Photoluminescence (PL) emissions for Bi2Te3 thin film samples of various thicknesses are examined and analysed. Raman study reveals the presence of two active modes.

Synthesis, characterization, biological activity, computational evaluation and molecular docking simulation of dimeric Cu(II) carboxylate complexes

Copper(II) carboxylate complexes are important in biological fields. In this study, five new dinuclear Cu(II) complexes having the general formulae [Cu2(Cl-PAA)2(DMSO)2] (1), [Cu2(Cl-PAA)2(phen)2] (2), [Cu2(Cl-PAA)2(bipy)2] (3), [Cu2(Cl-PAA)2(py)2] (4), [Cu2(Cl-PAA)2(Cl-Py)2] (5) were synthesized and characterized by FTIR and UV–Vis spectrophotometry. FTIR study supported the monodentate nature of the carboxylate in complexes 2 and 3 while bidentate bridging behavior of carboxylate was observed in complexes 1, 4 and 5. UV–Vis study revealed the presence of d-d transition in visible region, while charge transfer band was observed in ultraviolet region. Antimicrobial activities of complexes 1–5 were studied among which complexes 1, 2 and 4 showed good activities. The results of antioxidant assay demonstrated that free radical scavenging activity by Cu(II) complex containing 1,10-phenanthroline was higher compared to other complexes. All the synthesized complexes were optimized by DFT-d-based DMol3 module in Material Studio. After that, the quantum chemical parameters containing hardness, softness, and electrophilicity were calculated. Based on value of (ω), complex 2 showed the best biological activity that supported experimental studies. All complexes were investigated by molecular docking with cytochrome P450 14 alpha-sterol demethylase (1ea1), the docking findings demonstrated that complex 2 had the highest interaction with cytochrome P450 due to the biggest interaction energy of complex 2 as compared with other complexes. In addition, according to corrosion studies, complex 2 showed highest coating on the iron (110) surface protecting the iron from corrosion due to high adsorption value.

Effect of magnetic field on the structural, optical, and electrical properties of CdS nanoparticles in distilled water by using pulsed laser ablation

In this study, we investigated the impact that the incorporation of a magnetic field has on the properties of cadmium sulfide CdS nanoparticles as well as the performance of an n-CdS/p-Si heterojunction photodetector that was developed by the use of the pulsed laser ablation in a liquid method. Nd:YAG laser pulses (1.064 μm, 550 mJ) were utilized to ablate cadmium sulfide CdS nanoparticles in water. The synthesized nanoparticles were shown to have a polycrystalline hexagonal structure, as evidenced by the findings of the X-ray diffraction experiment, the crystallite size for cadmium sulfide CdS decreased from 4.611 nm to 4.518 nm. The lattice constants of cadmium sulfide CdS nanostructures were determined to be a = 4.1302, c = 6.702, and c/a=1.622. The strain and dislocation density of cadmium sulfide CdS exhibited an increase. Images taken from a field emission scanning electron microscope demonstrated the formation of spherical nanoparticles on the surface. A magnetic field was applied, increasing the CdS film's crystallinity. As a consequence of this enhancement, the particle size of the CdS decreased from 25.18 nm to 12.17 nm. A comparison was made between this and the size of the crystallites that appeared when no magnetic field was present. The EDS spectrum of magnetically prepared cadmium sulfide CdS films indicates the presence of Cd and S, and the weight percentage ratios [Cd]/[S], increase from 3.72 to 3.80. The transmission electron microscopy (TEM) pictures of CdS samples that were generated using a magnetic field contained particles of small size with a mean of 10.10 nanometers. From the FT-IR spectra of cadmium sulfide CdS prepared using a magnetic field within 400–4000 cm−1, the peaks (bands) of cadmium sulfide CdS at 617 cm−1 represent the bending vibration of Cd-S. As a result of the influence of a magnetic field, the optical energy gap of CdS nanoparticles increased from 2.30 eV to 2.72 eV, as indicated by the UV-Vis study. From PL emission spectra the values of the energy band gap of cadmium sulfide CdS increased from 2.45 eV at 505.7 to 2.47 eV when a magnetic field was applied. CdS NP films produced under the influence of a magnetic field were identified as having n-type characteristics by Hall effect assessments, Particle mobility was influenced by particle size. The effect of applying a magnetic field on the efficiency of the n-CdS/p-Si photodetector was investigated and analyzed. When a magnetic field was applied during ablation, the responsivity of n-CdS/p-Si heterojunction photodetectors increased from 0.498 A/W to 0.830 A/W at 510 nm. This was the result of the application of the magnetic field.

Biosynthesis of NiO nanoparticles using Senna occidentalis leaves extract: Effects of annealing temperature and antibacterial activity

In this work a cost effective and ecofriendly green method for the preparation of NiO nanostructures employing Senna occidentalis (S. occidentalis) leaves extract has been reported. XRD studies show that the 400 °C and 500 °C annealed nanostructures were authenticated as pure face centered cubic phase with an average crystallite size are about 27 nm and 15 nm, respectively. The SEM results show that both the annealed samples were nearly spherical with grain sizes ranging between 40 and 700 nm. The band gap of 400 °C and 500 °C annealed NiO nanoparticles (NPs) was estimated to be 5.28 eV and 5.40 eV, respectively from UV-visible studies while the occurrence of Ni-O stretching in the FTIR spectra validates the formation of NiO. Further this work witnesses that the NiO NPs synthesized from the green route offer better antibacterial activity. The observed maximum zone of inhibition of 500 °C annealed NiO NPs was found to be 20 mm and 19 mm for Serratia marcescens and Bacillus cereus strains and indicates that this material can serve as a prospective drug for biomedical application.

Synthesis of new multi-functionalized Schiff base derivatives based on vanillic acid: Antimicrobial activity, photophysical, DFT calculations and in-silico study

The paper reports the synthesis of novel multi-functional Schiff base derivatives (S1-S7) via Steglich esterification, thoroughly characterized by standard spectroscopic methods (1H NMR, 13C NMR, FT-IR and Mass spectrometry) and elemental analysis technique. Density Functional Theory calculations (including FMOs’, MEP, IR and UV–Visible), photophysical, molecular docking simulations, and in-vitro antimicrobial assays were employed to study the structure and reactivity of synthesized compounds. The study highlights significant antimicrobial activity of certain derivatives, which aligns with computational predictions. UV–Visible study identifies various transitions like π→π*, n→π* occurring in the system aligning with the theoretical absorption spectra. Biological studies reveal that compounds S1, S2 and S5 exhibit significant potency for antimicrobial investigation correlating with the computational study. Further, the calculated HOMO-LUMO band gap for S1-S7 molecules (3.29 eV) suggest their insulating nature. Notably, MEP study shows negative electrostatic potential near nitro group and the positive potential near alkyl groups indicating preferable site for electrophilic and nucleophilic attack, respectively. Moreover, molecular docking was implemented to computationally screen the multi-functionalized Schiff base along with molecular dynamics simulation including MM-PBSA energy calculation in order to discover the reasonable physiological significance ensuring stability of binding interactions of relevant molecules.

Fabrication of Silica Gel Reinforced, Cadmium Oxalate based Extrinsic Crystalline Materials and their Characterization

Cobalt-lead mixed cadmium oxalate (CoLMCO) and zinc-lead mixed cadmium oxalate (ZnLMCO) extrinsic crystalline materials were grown in oxalic acid embedded silica hydrogel. In an optimized gel environment, the extrinsic Co2+-Pb2+ and Zn2+-Pb2+ combinations fit well in the parental Cd2+ vacancies and emerged as distinct CoLMCO and ZnLMCO novel materials. The inherent properties of CoLMCO and ZnLMCO crystals were characterized by analytical and spectroscopic methods. Energy dispersive X-ray (EDX) analysis attached with field emission scanning electron microscope (FESEM) was employed to identify the chemical composition and morphology of the crystals. Fourier transform infrared (FTIR) spectral analysis confirmed the presence of oxalate group, water of crystallization and metal-oxygen bonds in the crystals. Thermal studies confirmed two phases of decomposition and ensured stability up to 1112.78 ºC for CoLMCO crystals and 1071.65 ºC for ZnLMCO crystals in a metal-oxide state. Bragg’s diffraction patterns revealed the high crystallinity of the materials and observed triclinic geometry in them. The UV-visible spectral studies of CoLMCO and ZnLMCO crystals showed maximum transparency to visible light and absorption in the UV region, possessing absorption maximum Amax = 1.588 and 1.276; optical band gap energies Eg = 5.638 eV and 5.845 eV, respectively. The V-I characteristics of the prepared crystals unveiled a feeble current flow (nA), exhibiting linear variation with applied DC voltage (0-200 V) leading leakage resistances of 1.187 GΩ (CoLMCO) and 5.176 GΩ (ZnLMCO). Dielectric constants of mixed crystals varied inversely with applied frequency and became almost stable at the mid-radio frequency range.

Photocatalytic Degradation of Transition Metal (Ni) Doped ZnS Nanoparticles Synthesized via Simple Solvothermal Route

Ni doped ZnS nanoparticles were obtained using the simple Solvothermal Microwave Irradiation (SMI) method in this research. This technique is cost-effective and results in a high level of uniformity in particle size. The sample's structural characteristics were examined utilizing XRD Technique, FESEM image, Elemental analysis of the as prepared sample obtained from EDX spectrum and their optical characteristics analysed by using UV-Visible absorption study. The XRD pattern of Ni doped ZnS nanoparticles were to obtain their crystallite size (D), lattice constant (a), and volume of the unit cell (V). As the concentration of Ni dopant increased (0, 2.5, 5.0) M %, the values of the lattice constant decreased, leading to an overall decrease in the volume of the unit cell. FESEM images reveals the sample have uniform surface morphology and EDX analysis give evidence for element Zn, Ni, S presents in the sample. Ni doped ZnS nanoparticle dimension strongly influences their optical characteristics. The optical bandgap, as obtained from UV-Vis measurements, ranges from 3.54 eV to 3.50 eV with doping concentrations varying from 0 M% to 5.0 M% .This adjustment in optical properties suggests that Ni-doped ZnS nanoparticles have diverse applications in optoelectronics, sensors, UV detectors, and as an efficient photocatalyst for degrading pollutants in water. The efficiency of the degradation of Methylene Blue dye by Ni doped ZnS nanoparticles was found to be 75.19%.

Electron Donor-Acceptor Complex-Assisted Photochemical Conversion of O-2-Nitrobenzyl Protected Hydroxamates to Amides.

The hydroxamic acid functionality is present in various medicinal agents and has attracted special interest for synthetic transformations in both organic and medicinal chemistry. The N-O bond cleavage of hydroxamic acid derivatives provides an interesting transformation for the generation of various products. We demonstrate, herein, that O-benzyl-type protected hydroxamic acids may undergo photochemical N-O bond cleavage, in the presence orabsence of a catalyst, leading to amides. Although some O-benzyl protected aromatic hydroxamates may be photochemically converted to amides in the presence of a base and anthracene as the catalyst, employing O-2-nitrobenzyl group allowed the smooth conversion of both aliphatic and aromatic hydroxamates to primary or secondary amides in good to excellent yields in the presence of an amine, bypassing the need of a catalyst. DFT and UV-Vis studies supported the effective generation of an electron donor-acceptor (EDA) complex between O-2-nitrobenzyl hydroxamates and amines, which enabled the successful product formation under these photochemical conditions. An extensive substrate scope was demonstrated, showcasing that both aliphatic or aromatic hydroxamates are compatible with this protocol, affording a wide variety of primary and secondary amides.

Synthesis of Amorphous and Various Phase-Pure Nanoparticles of Nickel Phosphide with Uniform Sizes via a Trioctylphosphine-Mediated Pathway.

Nickel phosphides are of particular interest because they are highly active and stable catalysts for petroleum/biorefinery and hydrogen production. Despite their significant catalytic potential, synthesizing various phase-pure nickel phosphide nanoparticles of uniform size remains a challenge. In this work, we develop a robust trioctylphosphine (TOP)-mediated route to make highly uniform phase-pure Ni12P5, Ni2P, and Ni5P4 nanoparticles. The synthetic route forms amorphous Ni70P30 nanoparticle intermediates. The reactions can be stopped at the amorphous stage when amorphous particles are desired. The amount of P incorporation can be controlled by varying the ratio of TOP to Ni(II). The mechanism for composition control involves the competition of the kinetics of two processes: the addition of the reduced Ni and the incorporation of P into Ni. Uniform Ni70P30 amorphous nanoparticles can be generated at a high TOP-to-Ni(II) ratio, where the P incorporation kinetics is made to dominate. Ni70P30 can later be transformed into phase-pure Ni12P5, Ni2P, and Ni5P4 nanocrystals of uniform size. The transformation can be controlled precisely by modulating the temperature. A UV-vis study coupled with theoretical modeling reveals Ni(0)-TOPx complexes along the synthetic path. This approach may be expanded to create other metal compounds, potentially enabling the synthesis of uniform nanoparticles of a greater variety.