TEM Studies Research Articles

Synthesis of Mixed-Phase TiO2–ZrO2 Nanocomposite for Photocatalytic Wastewater Treatment

The use of TiO2 nanoparticles for photocatalysis for the degradation of organic dyes under UV light for wastewater treatment has been widely studied. However, the photocatalytic characteristics of TiO2 nanoparticles are inadequate due to their UV light response and higher band gap. In this work, three nanoparticles were synthesized: (i) TiO2 nanoparticle was synthesized by a sol-gel process. (ii) ZrO2 was prepared using a solution combustion process and (iii) mixed-phase TiO2-ZrO2 nanoparticles were synthesized by a sol-gel process to remove Eosin Yellow (EY) from aqueous solutions in the wastewater. XRD, FTIR, UV-VIS, TEM, and XPS analysis methods were used to examine the properties of the synthesized products. The XRD investigation supported the tetragonal and monoclinic crystal structures of the TiO2 and ZrO2 nanoparticles. TEM studies identified that mixed-phase TiO2-ZrO2 nanoparticles have the same tetragonal structure as pure mixed-phase. The degradation of Eosin Yellow (EY) was examined using TiO2, ZrO2, and mixed-phase TiO2-ZrO2 nanoparticles under visible light. The results confirmed that the mixed-phase TiO2-ZrO2nanoparticles show a higher level of photocatalytic activity, and the process is accomplished at a high degradation rate in lesser time and at a lower power intensity.

Effect of Mn doping on structural, optical and photocatalytic properties of SnO2 nanoparticles

The bare and Mn-doped SnO2 products were prepared using a simple chemical precipitation process, which was discussed in the preparation aspect. XRD, SEM with EDS, TEM, and HRTEM studies were used to analyse the obtained Mn-doped SnO2. According to the UV-DRS data, SnO2 from Mn doping significantly reduced its band gap. The photoluminescence emissions of doped SnO2 exhibit an intensity reduction caused by the cross-relaxation process when compared to pure SnO2. The photocatalytic degradation of brilliant green (BG) using a bare SnO2 and Mn doped sample was investigated under visible light illumination. The Mn-doped SnO2 sample demonstrated a greater level of degradation (92.84%) due to its increased surface area (32.70 m2/g) and lower band gap (3.57 eV), which prevent the recombination of photogenerated charge carriers.

Synthesis of silver nanoparticles using aqueous leaf extract of Premna esculenta and in vivo evaluation of its hepatoprotective activity in Swiss albino male mice

In this study, silver nanoparticles (PE-AgNPs) were synthesized using Premna esculenta (PE) leaf extract, characterized by UV, TEM, TEM-EDX, XRD, DLS, and ICPOES studies. AgNPs were found to be stable at −35 mV with 26.157 ppm concentration. AgNPs were found triangular in shape with an average size of about 44 nm. Hepatoprotective activity was assessed in animal model using silymarin as standard drug. Biochemical parameters (serum AST, ALT, γGT, ACP, and ALP), inflammatory markers (IL 1β, IL 17, TNF α, and IL 10), and antioxidant markers (GSH, SOD, Catalase, and LPO) were assayed. Liver tissue was processed for histological analysis. Induction of hepatotoxicity increases AST, ALT, γGT, ACP, ALP, IL 10, LPO, and decreases IL 1β, IL 17, TNF α, GSH, SOD, and Catalase. PE-AgNPs treatment significantly decreases IL 10, LPO while IL 1β, IL 17, TNF α, GSH, and SOD were increased in animals. PE-AgNPs partially recovered CCl4-induced changes in liver histology.

Creep strengthening mechanisms of a superlattice γ′-strengthened Co–Al–W–Ta–Ti single crystal superalloy at steady-state conditions under compressive stresses

The strengthening mechanism of steady-state creep is a critical factor in developing advanced superalloys. In this study, the steady-state creep mechanisms of a superlattice γ′-strengthened Co–Al–W–Ta–Ti single crystal superalloy are investigated with the creep conditions of 750 °C/800 MPa, 900 °C/420 MPa and 1000 °C/137 MPa. Results suggest that the microstructures of steady-state creep samples are significantly different under the above three experimental conditions. A detailed TEM study shows that, Lomer-Cottrell locks and stacking faults interactions are responsible for the low creep rate at low temperature and high stress creep regime, dislocations cross-slip and the dislocation tangles contribute the main creep resistance at intermediate temperatures and moderate stress creep regime, interactions of stacking faults and dislocation networks are the strengthening mechanism for the high temperature and low stress creep regime. The steady-state creep rate of investigated alloy follows the classical power law equation, and the creep activation energy calculated by the power law equation is 378.46 kJ/mol. The results of this study provide insights into the effects of temperature and stress on steady-state creep mechanisms, and high activation energy makes the γ′-strengthened Co–Al–W–Ta–Ti single crystal superalloy an attractive candidate for further study as a high temperature structural material.

Biogenic synthesis, molecular docking, biomedical and environmental applications of multifunctional CuO nanoparticles mediated Phragmites australis

The demand for metal nanoparticles is increasing with the widening application areas while causing environmental impact including pollution, toxic byproduct generation and depletion of natural resources. Incorporating natural materials in nanoparticle synthesis can contribute toward environmental sustainability. This paper is concerned with the biogenic synthesis of copper oxide nanoparticles (CuONPs) mediated by the plant species Phragmites australis. UV–vis, FT-IR, TEM and SEM studies were used to characterize the obtained CuONPs. The synthesized nanoparticles' antibacterial efficacy against Escherichia coli and Staphylococcus aureus was assessed. The CuONPs' reducing power, total phenolic component content, and flavonoid content were all calculated. Additionally, the dye removal abilities of copper oxide nanoparticles using Brilliant Blue R-250 were studied. The CuONP synthesis was assessed morphological by change of color and in the UV–vis analysis by the SPR band around 320 and 360 nm. FT-IR was used to monitor the functional groups present in the synthesized CuONPs. The obtained CuONPs were spherical and between 70 and 142 nm in size, according to the SEM data and TEM analyses were in accordance with SEM results. Using disk diffusion, the CuONPs demonstrated substantial antibacterial efficacy against S. aureus and E. coli, with inhibition zones of 18.5 ± 0.8 and 12.7 ± 0.6 mm, respectively. The MBC and MIC values were 62.5 μg/mL against S. aureus and 125 μg/mL against E. coli. The antioxidant abilities of P. australis and CuONPs were also confirmed. The CuONP solution's total phenolic substance content was 9.44 μg of pyrocathecol equivalent per milligram of nanoparticle, and its total flavonoid content was 16.24 μg of catechin equivalent per milligram of nanoparticle. Additionally, the synthesized CuONPs were found to be well effective on industrial dye removal by demonstrating high decolorization of 98 %. Also, the antibacterial activity of CuONPs was investigated through the interactions with S. aureus FtsZ, dihydropteroate synthase and thymidylate kinase. In silico molecular docking analysis was applied in the confirmation of the binding sites and interactions of active sites. CuONP showed −9.067, −8,048, and −7.349 kcal/mol of binding energies in molecular docking analysis of FtsZ, dihydropteroate synthase and thymidylate kinase proteins respectively. The results of this study suggested the antimicrobial, antioxidant and decolorative effect of synthesized CuONPs that can be apply in multiple areas of R&D and industry.

Characterization and theoretical calculations of the T([formula omitted])/Al interface in 2024 alloys: TEM and DFT studies

In this study, we systematically investigated several typical interfaces of the T-phase (a precipitated phase in 2024 alloy), namely the T(200)/Al(403), T(101)/Al(4‾03) and T(200)/Al(301) interface and analyzed interface properties through first-principles calculations and HAADF-STEM (High-angle annular dark-field scanning transmission electron microscope) observations. The calculation results show that AlMn- terminated interface is the most thermodynamically stable of the different terminal interfaces in T(200)/Al(403) and T(101)/Al(4‾03) interface. Therefore, we also speculate that the T precipitated phase forms interface with aluminum matrix through the AlMn- terminated. By investigating the DOS(density of states) and the electron density difference of the interface, we prove that Al–Mn covalent bond is formed on the outer surface of the T phase. In addition, this work provides some basis for the analysis of the T phase and T/Al interface from an energy point of view through various data, which helps us to further investigate the properties of the interface.

Role of Superconducting Materials in the Endeavor to Stop Climate Change and Reach Sustainable Development

Progress in the mass production of newly developed bulk (Gd0.33Y0.13Er0.53)Ba2Cu3Oy “(Gd,Y,Er)123” and MgB2 systems is presented. Two batches of (Gd,Y,Er)123 pellets of 20 mm diameter and 7 mm thick were prepared in air by an infiltration growth “IG” process. Trapped field distribution profiles of fully grown bulk samples clearly showed that all samples were single-grain and the trapped field values were more than 0.5 T at 77 K, 1.3 mm above top surface. The best bulk exhibited the trapped field value of 0.63 T at 77 K. Ultra-sonication technique was employed for refining precursors of both (Gd,Y,Er)211 and boron. TEM studies revealed that boron powder subjected to ultrasonication was refined up to nanoscale. The micron-sized particles were reduced to nanoscale, which led to improvement of critical current by up to 36% in bulk MgB2 at 20 K and self-field. This progress in fabrication of high-performance LREBa2Cu3Oy and MgB2 superconducting bulks further promotes commercialization of superconductors’ production as a mode of sustainable technology.

Green synthesis of silver nanoparticles from aqueous leaf extract of Medinilla beddomei C B Clarke and its antimicrobial activity

Silver nanoparticles were synthesized from aqueous leaf extract of Medinilla beddomei C B Clarke and evaluated its antimicrobial activity against different bacterial and fungal strains. Here silver nanoparticles were synthesized through green route using leaves of M. beddomei, confirmed by colour change and UV-Visible spectroscopy. The silver nanoparticles were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy and X ray diffraction studies. The evaluation of antimicrobial activity of the silver nanoparticles was performed by agar well diffusion method against four bacterial strains and two fungal strains. The formation of silver nanoparticles after treatment was confirmed by the colour change of the aqueous leaf extract into dark brown. TEM and XRD studies revealed that the synthesized silver nanoparticles are almost spherical in shape with an average size of 18.88 nm. The silver nanoparticles synthesized from M. beddomei showed high antimicrobial activity for concentrations of 50µg/ml and 100µg/ml. The highest antimicrobial activity was found against Aspergillus niger. The zone of inhibition of fungal strain shown by A. niger (36.00 ±1.50 mm) at 100µg/ml was higher than that of Ciprofloxacin (28.00±1.57 mm) at 200 mg/ml, the positive control. The silver nanoparticles synthesized from aqueous leaf extract of M. beddomei possess high antimicrobial efficacy against pathogenic bacterial and fungal strains. It can be exploited well in the pharmaceutical industry and for nanomedicine also.

Synthesis & characterization of amino acid-based acrylamide derived amphiphilic block copolymer using a new xanthate and its influence on cell cytotoxicity & cell viability

The development of amino acid-based polymers was due to their unique properties and structures like of biocompatible polymers having sensitive effects for numerous medicinal and biological actions like biochemical sensing and controlled release of drugs. To achieve this, poly (N-vinylpyrrolidone) (PNVP) and its block copolymer poly (N-vinylpyrrolidone)-b-poly (N-acryloyl-L-phenylalanine) (PNVP-b-PNALP) were synthesized by using a xanthate i.e., ethyl 2-((isopropoxycarbonothioyl)thio)-2-methylpropanoate (IPX), which exhibits good control RAFT polymerization. The plot between molar mass and conversion yields a linear line which confirms the pseudo-first-order kinetics, and molar mass distribution (Ðm) was found between (1.50–1.24). Both polymers were characterized by 1H NMR, FTIR, DSC, TGA-DTA, GPC, and XRD analysis. TEM and DLS study of the aqueous solution of the block copolymer (PNVP-b-PNALP) exhibited self-assembly (119–160 nm with a few smaller particles of 91 nm). Different concentrations of polymers (200–0.75 μM) were evaluated for their toxicities on macrophages (RAW 264.7) and cancer (MCF7) cell lines. The polymers were found to be nontoxic as we did not observe any significant changes in the rate of proliferation of both cells even at higher concentrations (up to 100 μM). However, the polymers were found to induce apoptosis-like changes in the cancer cells up to 100 μM, albeit not significant.

Zinc oxide nanoparticles synthesized using Oldenlandia Umbellata leaf extract and their photocatalytic and biological characteristics

The aim of this study was to examine the environmentally friendly green production of zinc oxide nanoparticles (ZnO NPs) utilizing Oldenlandia Umbellata (OU) leaves extract, as well as to study the photo catalytic and biological activities of these particles. XRD, UV-Visible, FT-IR, SEM, EDAX, TEM and Zeta potential studies were used to investigate the purity and properties of as synthesized ZnO NPs. From the FT-IR investigations presenting functional groups were verified. The hexagonal form and wurtzite crystal nature were confirmed by SEM and XRD photographs. The decreasing zeta potential of −23.7 mV suggested the stability of OU-ZnO NPs, which was validated by Zeta potential and EDAX measurements. The OU-ZnO NPs' photo catalytic activity was also examined using their methylene red dye degradation potential. It also has a DPPH test that revealed it had a 66% radical scavenging activity. Furthermore, this substance was proven to be an effective anti-fungal agent against Candida albicans, which demonstrated a maximum mycelial inhibition of 12.5 ± 0.7. Additionally, the biosynthesized nanoparticles had high antibacterial activity verses all of the microbiological strains tested to varying degrees.

Cationic Solid SMEDDS of Efavirenz for Improved Oral Delivery: Development by Central Composite Design, In Vitro and In Vivo Evaluation

Efavirenz (EFV) is an anti-HIV drug with high dose and 40% oral bioavailability (BA). The aim was to improve the bioavailability by designing cationic solid SMEDDS. Solubility data, ternary phase diagrams, and central composite design were employed in design. Globule size, TEM, DSC, and SEM studies were used for characterization. Optimized L-SMEDDS contained 20mg of EFV, 10mg of Peceol, 43.5mg of Tween 80, and 40mg of Labrafac Lipophile WL-1349 and the characters included mean globule size-94nm, PDI-0.255, and ZP-28mV. Later, octadecylamine was added to get L-SMEDDS with + 38mV charge. L-SMEDDS was converted into solid S-SMEDDS by adsorbing onto silica carriers. Syloid XDP was preferred based on flow and oil adsorption capacity. The % drug (EFV) release from powder, L-SMEDDS, and solid SMEDDS were 14.04, 94.47, and 85 respectively in first 30min. TEM picture showed dispersed globules. DSC and SEM studies indicated the loss of drug crystallinity in S-SMEDDS. Pharmacokinetic (PK) studies in Wistar rats revealed 4.12 fold hike in BA for optimized cationic S-SMEDDS when compared to EFV suspension. Increased absorption could be due to the positive charge on globules. Thus, cationic S-SMEDDS emerged as a potential novel delivery system for improvement in BA and has scope for reducing the high dose for AIDS patients by future clinical studies.

Effects of Reaction Parameters on the Geometry and Crystallinity of Hydrothermally Synthesized ZnO Nanorods for Bio-Fouling Applications

In this present work, we have successfully synthesized vertical aligned ZnO nanorod arrays (ZnO NRs) on conductive stainless-steel substrate. These ZnO NRs were obtained by using a low temperature, low cost, and eco-friendly hydrothermal approach. The effect of the sol-gel deposited ZnO seed layer on the vertical alignment ZnO NRs has been thoroughly studied. Characterizations of the seed layer and the as-obtained nanorods were investigated using scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM), high-resolution transmission electron microscopy (HR-TEM), and water contact angles (WCA) measurement. SEM analysis shows that these nanorods were grown with a high uniformity and density over the entire substrate. TEM and XRD studies confirmed the hexagonal wurtzite structure of ZnO nanorods. Finally, field immersion tests using the optimized samples were conducted in a coastal sea environment to study biofouling settlement. To the best of our knowledge, there are few articles that investigate the influence of the seed layer deposited on stainless steel on the formation of vertically aligned nanorods for antifouling applications. The novelty of this work is manifested by optimizing the ZnO seed layer to obtain either thick or fine ZnO nanorods (NRs). Moreover, another novelty of this study is the use of the hydrothermal deposition of ZnO NRs on stainless steel for biofouling to replace paints in marine applications.

Histidine-Functionalized Diblock Copolymer Nanoparticles Exhibit Enhanced Adsorption onto Planar Stainless Steel.

RAFT aqueous emulsion polymerization of isopropylideneglycerol monomethacrylate (IPGMA) is used to prepare a series of PGEO5MA46 -PIPGMAy nanoparticles, where PGEO5MA is a hydrophilic methacrylic steric stabilizer block bearing pendent cis-diol groups. TEM studies confirm a spherical morphology while dynamic light scattering (DLS) analysis indicated that the z-average particle diameter can be adjusted by varying the target degree of polymerization for the core-forming PIPGMA block. Periodate oxidation is used to convert the cis-diol groups on PGEO5MA46 -PIPGMA500 and PGEO5MA46 -PIPGMA1000 nanoparticles into the analogous aldehyde-functionalized nanoparticles, which are then reacted with histidine via reductive amination. In each case, the extent of functionalization is more than 99% as determined by 1 HNMR spectroscopy. Aqueous electrophoresis studies indicate that such derivatization converts initially neutral nanoparticles into zwitterionic nanoparticles with an isoelectric point at pH 7. DLS studies confirm that such histidine-derivatized nanoparticles remain colloidally stable over a wide pH range. A quartz crystal microbalance is employed at 25°C to assess the adsorption of both the cis-diol- and histidine-functionalized nanoparticles onto planar stainless steel at pH 6. The histidine-bearing nanoparticles adsorb much more strongly than their cis-diol counterparts. For the highest adsorbed amount of 70.5mgm-2 , SEM indicates a fractional surface coverage of 0.23 for the adsorbed nanoparticles.

Preparation and Statistical In-vitro Evaluation of Covalent Functionalized Multi Walled Carbon Nanotube 5-Fluorouracil Conjugates

In 21st century, carcinoma is predicted to be a remarkable health problem. The condition of the cancer patients will be critical when it comes to its remedy by chemotherapy using artificial anticancer molecules with various chemo side effects. In the field of nanotechnology, the nanomaterials are rapidly developing. Nanomaterials become admirable and necessary in lot of areas of human interest because of their exclusive size - dependent properties, chemical reactivity, conductivity, and enlarged strength. Carbon nanotubes (CNT) are referred to as nanomaterials. In this present world of medical research and the bio sensing technology has the capability to transform the CNT in the field of efficient medicine delivery, biosensor strategies for ailment treatment and for the health tracking. Our present work is an strive to probe the loading and release of 5- Fluorouracil from Multi Walled Carbon Nanotubes (MWCNTs) to cancer tissues. MWCNTs were subjected to covalent functionalization by using the strong acids, the oxidised MWCNTs are obtained in covalent functionalization process. Through this operation, carboxy (-COOH) groups are set up at the open sides (tips) and at the defects on the sidewalls of MWCNTs and then covalent functionalized MWCNTs were loaded with 5- Fluorouracil to prepare covalent functionalized MWCNTs-5-Flourouracil conjugate. Covalent functionalized MWCNTs-5-Flourouracil conjugate were subjected for SEM studies, TEM studies, particle size, zeta potential, drug entrapment efficiency and in vitro drug release. The release of drug shows longer than 40 h from covalent functionalized MWCNTs-5-Flourouracil conjugate and thus to manage the release of drug in controlled manner. The present research work presents esteemed, novel, and easy to prepare formulation of MWCNTs with superior drug entrapment efficiency with increased hydrophilic property of MWCNTs, and thus increases the bioavailability at selected site with narrow systemic toxicity.

Application of Quasihexagonal Pt@PdS2-MWCNT catalyst with High Electrochemical Performance for Electro-Oxidation of Methanol, 2-Propanol, and Glycerol Alcohols For Fuel Cells

Today, it is very important to develop energy conversion devices such as fuel cells in order to meet the demand for clean energy. In fuel cells, on the other hand, nanostructures are frequently used. To benefit from this activity, the dendritic semi-hexagonal Pt@PdS2-MWCNT catalyst was synthesized using the hydrothermal method within the scope of the study. According to XRD results, it was determined that the crystal structure of Pt@PdS2-MWCNT was formed, and it had a crystal size of 4.11 nm. In addition, because of TEM studies, it was observed that there were particles of 4.02 nm on the MWCNT surface and a Quasihexagonal structure was obtained. The resulting catalyst was used in fuel cell application as an anodic catalyst for the oxidation of methanol, 2-propanol, and glycerol. The catalyst synthesized in the results obtained; Current peaks of 86.71 mA/cm2, 67.32 mA/cm2 and 58.44 mA/cm2 were obtained in cyclic voltammetry for methanol, 2-propanol, and glycerol, respectively. At the same time, scanning speed, chronoamperometry and long-term stability tests were performed for electro-oxidation stability and stability of the catalyst for methanol, 2-propanol and glycerol oxidations using sulfuric acid buffer solution. The results provided better stability and activity of the catalyst, with a higher current peak and 11.7% retention for methanol oxidation compared to other alcohols.

Solvothermal Synthesis of Spherical Alumina: Delving into the Formation Mechanism and Morphological Change with Phase Transformation

AbstractSpherical shaped mesoporous alumina was synthesized by a simple solvothermal process at 110 °C/24 h using aluminum nitrate as precursor in the presence of glycerol, diethyl ether and propanol followed by calcination at 900–1100 °C. The transformation of solid spherical γ‐Al2O3 at 900 °C into layered shell spherical α‐Al2O3 at 1000–1100 °C was governed by stepwise temperature gradient (ΔT) along the radial direction of interface with adhesion and contraction forces. XRD analysis confirmed the formation of γ‐Al2O3 at 900 °C and its conversion to α‐Al2O3 at 1000 °C. The N2 adsorption–desorption results showed BET surface area and average pore diameter of γ‐Al2O3 as 77.58 m2 g−1 and 3.7 nm, respectively. The particle size of alumina spheres was in the range of 1–3 μm as confirmed by FESEM and TEM studies. The HRTEM images indicated lattice spacing of 0.21 and 0.23 nm corresponding to γ‐Al2O3 with (400) plane and α‐Al2O3 with (110) plane, respectively. A tentative formation mechanism and the role of glycerol have been explained.

Pristine TiO2 and Sr-Doped TiO2 Nanostructures for Enhanced Photocatalytic and Electrocatalytic Water Splitting Applications

Pristine TiO2 and Sr-doped TiO2 (1%, 2.5% and 5%) nanoparticles were synthesized at low temperatures via an eco-friendly hydrothermal route for water-splitting applications. XRD, EDAX and Raman analysis were performed to analyze the crystallinity, purity and structure of the as-synthesized materials. TEM, SEM, BET and UV-DRS studies were carried out to elucidate the size, morphology, surface area and optoelectronic properties of the nanoparticles. High surface areas of 169, 182, 178 and 141.16 m2 g−1 for pristine TiO2 (12 ± 0.6 nm) and 1% (11.1 ± 0.6 nm), 2.5% (12.1 ± 0.6 nm) and 5% (13 ± 0.7 nm) Sr-doped TiO2 nanoparticles were obtained, respectively. One-percent Sr-doped TiO2 nanoparticles were found to be active photocatalysts, as they showed higher hydrogen production (26.30 mmolgcat−1). Furthermore, electrocatalysis was investigated for HER and OER in 0.5 N H2SO4 and 0.1 N KOH electrolytic solutions using calomel as a reference electrode, revealing that 1% and 5% Sr-doped TiO2 showed maximum current density for both HER (≈10 mA/cm2) and OER (≈2.49 mA/cm2), with an onset potential of 0.96 V for HER and 1.55 V for OER, and Tafel slopes of 84.09 and 91.60 mV/dec, respectively.

Применение просвечивающей электронной микроскопии для исследования функционального наноэлемента

Using the focused ion beam probe method, cross-section sample of a single functional device of micron dimensions were cut out for STEM and TEM studies. The use of analytical methods of transmission electron microscopy made it possible to obtain accurate data on the geometric parameters of nanoscale functional devices, the phase and elemental composition of functional element material, as well as on the concentration of free electrons at the Fermi level in the nanoelement material.

An efficient metal oxyhydroxide catalyst for electrocatalytic hydrogen evolution reaction

An enormous amount of research is being carried out in electrocatalysis, notably for hydrogen evolution reactions (HER), because of the growing demand for sustainable and clean energy sources. Electrochemical water splitting, which results in hydrogen gas, is a practical path to a carbon–neutral energy system. It is essential to create efficient, cost-effective electrocatalysts to achieve this. In recent years, FeOOH-based catalysts have emerged as intriguing HER candidates due to their excellent activity, stability, and accessibility. This work investigates FeOOH quantum dots as an electrocatalyst for hydrogen evolution and sheds an insight on their unique properties, manufacturing processes, and catalytic activity. The quantum dots have demonstrated good electrochemical activity due to their increased surface area and noticeably higher active sites. With the use of UV–vis spectroscopy, XRD, TEM, and electrochemical studies of the catalyst activity, the catalyst has been well characterised. The catalyst demonstrated amazing activity, a decreased Tafel slope, and a lower overpotential, making it a potential option for use in the future.

Synthesis and Spectroscopic Characterization of Zinc Sulphide nanoparticles using Microwave irradiation of Zinc complex of Thiosemicarbazone ligand as a Single Molecular precursor : Pharmacological activities

Single molecular precursors are appropriate starting materials for synthesis of semiconductor nanoparticles (NPs), which allow for the control of atomic ratio, monodispersity, composition and particle size of nanoscaled metallic sulfide nanoparticles. In the present study, we have reported the synthesis of nanostructured chalcogenides pharmacologically active active zinc sulfide nanoparticles (ZnS NPs) using Zn (II) ion inserted thiosemicarbazone ligand as a single molecular precursor .The precursors were thermally pyrolysized using high energy microwave radiations to obtain very fine ZnS nanoparticles. In this synthesis, we use DMSO as a nonpolar solvent for the synthesis of all compounds. The heating of Zinc complex in the non- aqueous environment of DMSO plays a very crucial role in decreasing reaction time, reducing the chances of side reactions and proper conversion of Zn complex into ZnS nanoparticles. In this reaction Zn complex of thiosemicarbazone ligand provides both Zn2+ and S2- ions for synthesis of ZnS nanoparticles. The microwave synthesis of ZnS NPs from Zn complex is a very simple, fast, highly effective, efficient and low cost method. All synthesized compounds were characterized by various structural, electronic, vibrational, optical, morphological and pharmacological characterizations. The prepared ZnS NPs were found to crystallize in cubic phase, which generally forms at low temperatures, with the dimensions dependent upon the molar ratio of molecular precursors used. Synthesized ZnS nanomaterials had surface sulfur vacancies that extend their absorption spectra towards the visible region and decreased the bond gap. This allowed ZnS nanoparticles to demonstrate various pharmacological activities like antibacterial, antioxidant and anti-inflammatory activities under normal conditions. Powered X-ray diffraction studies confirms the formation of well -defined equispaced crystalline ZnS NPS. TEM and FE SEM microscopic studies confirmed the elongated tubules structure of ZnS NPs with an average particle size of 60 nm. Sharpe electronic absorption band at 390 nm indicates the synthesis of good quality ZnS NPs. The FT-IR spectral studies confirmed the presence of Zn-S stretching, N-H bending and C=N stretching, vibrations in molecular precursor as Zn(II) complex. The thermal analysis of molecular precursor was performed to investigate the thermal stability of zinc complex. The Zn complex was stable up-to 3800 c. All synthesized compounds demonstrated excellent pharmacological activities like antibacterial, antioxidant and antiinflammatory activities as compared to standards used in analysis of compounds. The microwave synthesis of ZnS nanoparticles via single molecular precursor in proper stoichiometric ratios is an excellent and an efficient method for synthesizing highly effective bioactive agents which can be considered as good drug candidate for the treatment of various diseases in future