Search

Lithium-doped anatase-TiO2 nanoparticles (LixTi1-xO2 NPs, x = 0, 0.05, 0.10, 0.15 and 0.20) could be synthesized by a simple sol–gel process. X-ray diffraction (XRD) results displayed the tetragonal (space group: I41/amd) of polycrystalline TiO2 anatase phase. The spectroscopy results of Raman and FT-IR confirmed the anatase phase of TiO2 through the specific modes of metal oxides vibration in the crystalline TiO2. Surfaces micrographs by scanning electron microscope (SEM) of agglomerated LixTi1-xO2 NPs showed a spongy like morphology. Transmission electron microscope (TEM) illustrated a cuboidal shape of dispersed NPs with particle size distributed in a narrow range 5–10 nm. Bruanauer Emmett-Teller (BET) results showed the increased surface area of LixTi1−xO2 NPs with increasing Li content. LixTi1-xO2 NPs (x = 0.05–0.20) working electrodes illustrated a pseudocapacitive behavior with excellent electrochemical properties through the whole cycles of GCD test. Interestingly, Li0.1Ti0.9O2 NPs electrode illustrated a high performance in terms of maximum specific capacitance 822 F g−1 at 1.5 A g−1 in 0.5 M Li2SO4 electrolyte, with excellent capacitive retention 92.6% after 5000 cycles GCD test. [ABSTRACT FROM AUTHOR]

Magnetite nanoparticles (Fe3O4) were prepared by chemical coprecipitation method using ferric chloride (FeCl3) and heptahydrate ferrous sulfate (FeSO4·7H2O) salts employing sodium hydroxide (NaOH) as a precipitant. To determine the size, shape, and chemical makeup of the produced magnetite nanoparticles, the generated powders were examined by transmission electron microscope, scanning electron microscope, atomic force microscope, and X-ray diffractometer. It was found that the magnetite powder had made a face-centered cubic crystal structure and spherical-like particle form with particle diameters of about 30 nm. The magnetic properties of magnetite nanoparticles were evaluated using a vibrating sample magnetometer. The obtained superparamagnetic properties of the produced nanoparticles, with saturation magnetization and coercivity of 50.75 emu/g and 30.09 Oe, respectively, allow them for applications in drug delivery, MRI contrast agent, catalysis, degradation of antibiotics, antibacterial activity, removal of heavy metals and organic dyes, etc. [ABSTRACT FROM AUTHOR]

The present research is focused on synthesis of silver/gold nanoparticles using Caralluma sarkariae root extracts (CSR-AgNPs and CSR-AuNPs) used as capping/reducing agents and successfully carry out the pharmacological studies. The as-prepared CSR-AgNPs and CSR-AuNPs were systematically characterized using various analytical techniques. Moreover, the formation of CSR-AgNPs & CSR-AuNPs was confirmed by SPR values observed at 432 and 537 nm in UV–Visible spectroscopic. Morphological information of CSR-AgNPs & CSR-AuNPs were investigated using scanning electron microscope (SEM) and high-resolution transmission electron microscope (HR-TEM) analysis and as-synthesized nanomaterials were spherical in nature with mean size of 20 and 22 nm, respectively. The prepared nanoparticles clearly proven that the as-prepared nanoparticles exhibit high performance efficiencies in terms of in vitro antioxidant, anti-inflammatory, antibacterial and antifungal activities. The wound healing activity of as-fabricated CSR-AgNPs and CSR-AuNPs were carried out separately using three different methods such as in vitro scratch assay, MTT assay, and fluorescence staining methods. Furthermore, the fibroblast L929 cells were used for the wound healing activity of both nanoparticles and aqueous CSR extract in in vitro scratch assay. Moreover, the wide range of diseases could be treated by using the nanoparticles as-synthesized due to their outstanding pharmacological activities. [Display omitted] • Biosynthesis of AgNPs and AuNPs using Caralluma Sarkariae root extract. • Both AgNPs and AuNPs examined here has excellent pharmacological activities. • The formation of AgNPs and AuNPs were confirmed by different analytical techniques. • Compared to plant extract, both nanoparticles showed greater anticancer activity. [ABSTRACT FROM AUTHOR]

The reproducible synthesis of boron nitride (BN) nano-onions by lamp ablation is reported, exclusively from hexagonal BN precursor powder in vacuum, in a one-pot procedure that is free of toxic or harmful reagents, uncomplicated, potentially scalable and rapid. A high-resolution Scanning Electron Microscope image shows a "forest" of such nano-onions as they evolve between precursor flakes. A Transmission Electron Microscope image illustrates the range of nano-onion sizes and shapes. A coarse schematic of the proposed formation mechanism is also shown. [Display omitted] We report the generation of boron nitride nano-onions (BNNOs) from pure hexagonal-BN crystallite powder in vacuum, via a one-pot, non-toxic, catalyst-free, rapid and potentially scalable high-temperature lamp ablation procedure. An array of characterization procedures revealed nanoparticle (a) shapes and sizes, morphing from polyhedral for diameters of order 101 nm to quasi-spherical at diameters of order 102 nm, and (b) composition, with a 1:1 B:N ratio while also confirming the absence of contaminants. A formation mechanism is proposed whereby BNNOs evolve from the initial thermal exfoliation of the bulk precursor powder into nano-platelets. They fold and close into hollow nano-cages that are more stable thermodynamically. Reactor temperatures were measured to be ∼ 1500–1600 K for experiments yielding the largest amounts of BNNOs. A relatively narrow range of ∼ 1300–1800 K can be established for viable BNNO generation. Structural modeling sheds light on the relative stability of the nanostructures as a function of shape, size and number of layers. [ABSTRACT FROM AUTHOR]

ZnO and cadmium (Cd)-doped ZnO (Zn1-xCdxO) nanoparticles with various compositions (0.0 ≤ x ≤ 0.8) were synthesized by sol-gel method. Structural, morphological, and photocatalytic properties as well as blood compatibilities of Zn1-xCdxO nanoparticles were investigated. While X-ray diffraction (XRD) applying the Rietveld refinement method was used to characterize the structural properties, scanning electron microscope (SEM) and transmission electron microscope (TEM) were used to investigate the surface morphology. It was found that the nanoparticles up to x < 0.03 Cd concentration had single phase of ZnO hexagonal wurtzite structure. Above x ≥ 0.03 Cd concentration, two phases (ZnO and cadmium oxide (CdO)) were observed. SEM images with different magnifications revealed the dense, quasi-spherical, and agglomerated morphology of Zn1-xCdxO nanoparticles. The elemental compositions of Zn1-xCdxO nanoparticles have also been studied by EDX analysis. The photocatalytic activities and blood compatibilities of Zn1-xCdxO nanoparticles were studied by the photocatalytic degradation tests of crystal violet (CV) and hemolysis tests and respectively. In the photocatalytic activity tests, two samples Zn0.90Cd0.10O and Zn0.80Cd0.80O stood out with photodegradation percentages of 69.9% and 72.8%. Among the Cd-doped nanoparticles, the Zn0.40Cd0.60O sample showed the highest blood compatibility with the weakest photocatalytic performance (degradation percentage; 32.2%). Structural properties, photocatalytic performance, and hemolytic potential of Zn1-xCdxO nanoparticles were investigated and compared with those of pure ZnO nanoparticles. [ABSTRACT FROM AUTHOR]

Since the development of bacterial resistance towards antibiotics has the potential to limit the effectiveness of antibiotics in the treatment of infectious diseases, it is necessary to try different strategies to provide alternatives. In order to solve the problems, this work used silver nanoparticles‐loaded polydopamine‐modified montmorillonite (AgNP/PDA−Mt) to cope with the infection of the gram‐negative bacteria Escherichia. Coli and the gram‐positive bacteria Staphylococcus. aureus. Polydopamine‐modified montmorillonite (PDA−Mt) was used to reduce silver ions into silver nanoparticles through the hydroxyl groups of polydopamine. The chemical properties and morphology of AgNP/PDA−Mt were analyzed by X‐ray diffraction spectroscopy (XRD), fourier transform infrared spectroscopy (FT‐IR), transmission electron microscope (TEM), scanning electron microscope (SEM), etc. Also, its antimicrobial property has been investigated. The results showed that AgNP/PDA−Mt possessed significant sterilization at low doses. And the results had been shown its acceptable biocompatibility. [ABSTRACT FROM AUTHOR]

Niobium pentoxide (Nb2O5) is a promising heterogeneous acid catalyst because of its water‐tolerant acidity. However, the reactivity of Nb2O5 is limited to the surface of a bulk material; thus, its catalytic activity is generally lower than homogeneous catalysts. Nano‐sized Nb2O5 shows superior activity but has low stability and recoverability. We develop spiky‐shaped Nb2O5 composed of radially grown nanorods, which show high stability but low acidity. In this study, an Al‐doping method and the doping effect on the acidity and nanostructure of the spiky‐shaped Nb2O5 are demonstrated. Al of 1–6 mol% is doped in Nb2O5 while maintaining the spiky nanostructure using an Nb–Al composite oxalate as a precursor. Scanning transmission electron microscope analysis results show that the doped Al ions are homogeneously dispersed in the structure. Al doping increases the catalytic activity, where 4 mol% Al‐doped Nb2O5 shows the highest production rate of 2‐phenyl‐2‐phenylaminoacetonitrile in a Strecker reaction. From the acid analysis and Raman spectroscopy, it can be concluded that the Al doping is effective in adjusting acidity and in enhancement of catalytic activity due to creation of NbO4 and distorted NbO6. These are produced by defect formation and lattice distortion caused by differences in valence and ionic radius between Al and Nb. [ABSTRACT FROM AUTHOR]

In this study, zinc ferrite nanoparticles with a diameter of less than 50 nm were synthesized. Using XRD (X-ray Diffraction), Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) the morphology and structure of this ferrite was investigated. The formation of spinel phase in Zn-Mn ferrite was shown by X-ray analysis. SEM photograph has shown spherical shape of nanoparticles and the dimensions of the samples were confirmed by Transmission Electron Microscope (TEM) at the nanoscale. Using the Debye-Scherrer formula, the size of Mn ferrite nanoparticle crystals was calculated to be about 13 nm. To check the properties related to the sensitivity of this ferrite, a fully insulated Plexiglass box was used and placed in it. By injecting 1 mL of liquid and vapor it, we will have 200 ppm concentration of each sample in this box. Then the injected vapored sample in this box is exposed to the ferrite. After this step, the conductivity of the ferrite in a closed circuit was changed. By changing the sample type, amount of this conductivity was varied. Five gases were tested in this project: ethanol, dimethyl formamid, carbon tetrachloride, acetonitrile and acetone. Among these samples the carbon tetrachloride had the best sensitivity performance. Finally, the sensor equation for carbon tetrachloride was extracted by applying different concentrations of it from 20 to 200 ppm. [ABSTRACT FROM AUTHOR]

This study aims at the characterisation of red and orange glass tesserae from the 4th-century Roman villa of Noheda (Spain). Due to the limited number of analyses available for such ancient materials, many questions remain unanswered about the production processes in the Roman period. Six samples were chosen for their hue variations, including two samples showing banded patterns of red and orange. Differences in copper speciation were investigated by X-ray absorption spectroscopy and compared with colour and compositional variations obtained by EPMA. The shapes and sizes of colouring crystals could be investigated using scanning and transmission electron microscope imaging. The brown-red colour is due to metallic copper nano-particles and corresponds to a low-copper and low-lead group usually described in the literature. The orange samples and bands are coloured by copper oxide C u 2 O nanoparticles with remaining Cu+ in the glass and have greater contents of Cu. Compositional analyses reveal that the same base glass is used in the red and orange bands with additions of Cu, Sn, Pb and probable Fe. Furthermore, based on our results and on the literature review, a high-copper low-lead group of glasses highlights the variability of compositions observed in cuprite colours. [ABSTRACT FROM AUTHOR]

The efficacy of nanoencapsulation as a technology for enhancing the solubility of active substances has been demonstrated. In this particular investigation, Ganoderic acid DM (GA-DM) was encapsulated within sodium alginate nanoparticles (NPs) using the ionic crosslinking method. The confirmation of the successful loading of GA-DM was ascertained through the analysis of Fourier transform infrared spectrum (FTIR). Empirical evidence derived from the examination of scanning electron microscope (SEM) images, transmission electron microscope (TEM) images, atomic force microscope (AFM) images, and dynamic light scattering (DLS) demonstrated a regular distribution and spherical morphology, with an average particle size of approximately 133 nm. The investigation yielded an encapsulation efficiency of 95.27 ± 0.11 % and a drug loading efficiency of 21.17 ± 0.02 % for the prepared sample. The release kinetics of SGPN was fitted with the Korsmeyer-Peppas kinetic model corresponding to diffusion-controlled release. The incorporation of GA-DM into sodium alginate nanocarriers exhibited a mitigating effect on the cytotoxicity of HaCat and B16, while also demonstrating inhibitory properties against tyrosinase activity and melanin formation. [ABSTRACT FROM AUTHOR]

Zinc oxide and zinc sulphide nanoparticles were produced using the sol-gel method. We employed nanoparticle identification methods for the examination of several factors. The precursor solutions are converted into an intermediate state that mimics gel during the sol-gel process, and then solidified. This technique provides fine control over the size, shape, and crystallinity of the resultant ZnO nanoparticles, hence modifying their electrochemical behaviour in the context of supercapacitor applications. An X-ray diffraction (XRD) examination revealed that the synthesized ZnO nanoparticles had a hexagonal character, while the ZnS nanoparticles had a cubic nature with diameters of around 22 nm and 36 nm, respectively. A transmission electron microscope (TEM) and a scanning electron microscope (SEM) are used to study the morphology and structural analysis. A particle size, surface area, production methods and testing settings are only a few of the variables that affect certain capacitances. In general, ZnO is recognized for displaying a certain capacitance that is frequently cited as being higher than ZnS. At a scan rate of 5 mV, the specific capacity of ZnO nanoparticles was found to be 33.2 F/g, whereas that of ZnS nanoparticles was found to be 6.5 F/g at a scan rate of 10 mV. One way to monitor pseudo capacitive behavior is by cyclic voltammetry. [ABSTRACT FROM AUTHOR]

Background: Nanotechnology is a fast developing science which has various applications in agriculture. Nanoparticles are broadly defined as the small particles with at least one-dimension size between 1 and 100 nm in diameter. Nanomaterials have the potential to penetrate the seed coat and enhance the ability of absorption and utilization of water, which stimulates enzymatic system and ultimately improves germination and seedling growth. The present study was undertaken to investigate the effects of nanoparticles and commercially used chemicals on breaking dormancy of Amorphophallus corms. Methods: Silver (Ag), zinc oxide (ZnO), titanium dioxide (TiO2 ), cerium oxide (CeO) and zero valent iron (ZVI) nanoparticles were synthesized successfully using chemical method and characterized for its size, shape and properties using Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), Particle Size Analyzer (PSA) and Raman spectroscopy. Freshly harvested corms of Amorphophallus were treated with different concentrations (50 and 100 mg kg-1) of these five nanoparticles and commercially used chemicals viz., thiourea (100 and 200 mg kg-1) and potassium nitrate (1000 and 2000 mg kg-1), with three different soaking periods (2, 4 and 6 h). Result: The analysed data indicated that corms treated with ZnO @ 100 mg kg-1 for six hours registered the minimum number of days (47.0 days) for sprout emergence. The maximum sprout length (23.50 cm), sprout diameter (6.35 cm), pseudo stem length (31.00 cm), pseudo stem girth (7.35 cm) and vigour index (1591.7) were recorded in TiO2 @ 50 mg kg-1 for two hours. [ABSTRACT FROM AUTHOR]

Composite materials are materials that are made of two or more materials that remain separate and differ on a macroscopic level while forming a single component so as to produce a composite material that has different mechanical properties and characteristics from the material it forms. Particle composite materials consist of particles held together by a matrix. In this study, an epoxy resin matrix was used with Polymesoda erosa clam shell nanopowder filler. Nano-sized fillers have many advantages over macro-sized ones. The nano-sized particles will have a high surface area, thereby increasing the mechanical strength of the material. The powdered nanoparticles produced will be analyzed using Fourier Transform Infrared (FTIR), Transmission Electron Microscope (TEM), and Scanning Electron Microscope (SEM). Based on the results of SEM and TEM, the nanopowder of clamshell has a size below 100 nm. The FTIR results of the powdered shellfish showed the presence of carbonate bonds C-O, C=O, and Ca-O. [ABSTRACT FROM AUTHOR]

Starch stain is a common stain on paper artifacts. This stain leads to deformation of the surface of the paper and promotes the growth of microbiological deterioration. This study aims to use nanoparticles with an α-amylase enzyme to improve its quality for removing this type of stain from the surface of paper artifacts. Accelerated heat aging was used on starch stain applied on the new paper samples. The α-amylase enzyme was prepared. Silver and gold nanoparticles were biosynthesized by local fungal isolation. The produced silver and gold nanoparticles were characterized by using different techniques of analysis (UV- Visible spectroscopy, Transmission Electron Microscope (TEM), and X-Ray diffraction (XRD) analysis). Different concentrations of Ag-NPs and Au-NPs were added to the α-amylase reaction mixture to enhance its activity for removing starch stains. Some analytical techniques were also used for the evaluation of the efficiency of α-amylase and nanoparticles for removing starch stains (Color measurement, Scanning Electron Microscope (SEM), and pH measurement). The results proved that Ag-NPs at 20 microliters increased the activity to about 160%, whereas Au-NPs enhanced the activity to about 140% at a concentration of 5μL. The results showed that α-amylase enzyme incorporated with Ag-NPs exhibited better results more than its use alone. The addition of Ag-NPs to α-amylase enzyme for the removal of starch stain reduced the total color differences, improved the surface morphology. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, a novel DHA-loaded nanoparticle with PLGA and chitosan (PCSDNP) was successfully prepared. The structure of PCSDNP and DHA-loaded PLGA nanoparticles was measured by transmission electron microscope, scanning electron microscope, and differential scanning calorimeter. The interaction strength between DHA, PLGA, and chitosan was evaluated through Fourier transform infrared spectroscopy. The curves of controlled DHA release and stabilities for different environmental factors of two NPs were evaluated. Importantly, two NPs were almost regularly spherical and the interactions were hydrogen bonds and electrostatic interactions between PLGA and chitosan. These NPs had a good encapsulation rate (80.45%) and high-water solubility than the free DHA molecule. In simulated gastrointestinal fluid, two NPs showed a controlled-release pattern. Overall, PCSDNP had better stability and controlled-release effect with the synergy between CS and PLGA under the conditions of pH (2– 7), ionic strength (0– 500 mM), storage time (0– 42 d), and temperature (30– 80 °C). [Display omitted] [ABSTRACT FROM AUTHOR]

The present study focuses on the novel synthesis of cerium oxide (CeO 2) nanoparticles from cerium nitrate hexahydrate by using Azadirachta indica (neem) leaf extract. The parameters associated with the green synthesis process were optimized utilizing the response surface methodology (RSM) paired with the genetic algorithm (GA) to produce a higher yield rate. The experiment run order for the CeO 2 green synthesis is then generated using the central composite design in RSM. The regression equation was used as an optimization function, and the optimal values were identified through GA. Using optimized input process parameters, 0.3 g/10 mL of precursor concentration and 5 mL of Azadirachta indica leaf extract centrifuged for 20 min in the green synthesis process resulted in a maximum yield of 15.49 % CeO 2 nanoparticles. The synthesized CeO 2 nanoparticles are characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), particle size distribution, and zeta potential analyses, which are used to ensure their presence in the green synthesis process. Subsequently, the green synthesized CeO 2 nanoparticles are dosed as an additive to the cotton seed biodiesel (CSB) at different proportions of 25, 50, and 75 ppm, respectively. The prepared biofuel's physico-chemical properties were measured as per ASTM standards and are closer to the diesel fuel. As a result, it was noted that optimizing the green synthesis process parameters gives a maximum rate of CeO 2 yield. It is possible to efficiently use the CSB with CeO 2 nanoparticles as a suitable replacement for diesel fuel. [Display omitted] • Novel leaf extract for the sustainable synthesis of CeO 2 nanoparticles. • Green synthetic CeO 2 yield forecasted by RSM's central composite design. • A hybrid RSM-genetic algorithm approach to process parameters optimization. • A characterization study was done on environmentally friendly CeO 2 nanoparticles. [ABSTRACT FROM AUTHOR]

A prospective novel technique has been developed for green synthesis of iridium nanoparticles of rod shapes for the first time with simultaneous formation of keto-derivative oxidation product with a yield of 98.3 %. This takes place by reduction of hexacholoroiridate (IV) by using sustainable pectin as a powerful reducing agent biomacromolecule in acidic media. The formation of nanoparticles (IrNPS) was identified by Fourier transform infrared (FTIR), Transmission electron microscope (TEM), X-ray diffraction (XRD), and Scanning electron microscope (SEM) investigations. The TEM morphology showed that the iridium nanoparticles were of crystalline rod shapes on contrary to the spherical shapes reported on all synthesized IrNPS earlier. The rates of nanoparticles growth were followed kinetically using a conventional spectrophotometer. The kinetic measurements revealed a unity order reaction in [IrCl 6 ]2− as oxidant and fractional first-order in [PEC] as a reducing agent, respectively. A decrease in the reaction rates was noticed with increasing the acid concentration. Kinetic evidence reveals the creation of intermediate complex as transient species prior to the slow step. Such complex formation may be facilitated by the participation of one chloride ligand from [IrCl 6 ]2− oxidant forming a bridge between the oxidant and reductant in such formed intermediate complex. Plausible reaction mechanisms for electron transfer pathway routes consistent with the kinetics observations were discussed. • Novel methodology for synthesis of nanoparticles using carbohydrate polymers • Green synthesis of iridium (0) nanoparticles of rod shapes by reduction of [IrCl6]2- by pectin • Identification of nanoparticles by FTIR and TEM techniques • Determination of the nanoparticles growth rates and nature of electron-transfer pathway routes • A plausible reaction mechanism for nanoparticles formation has been suggested and discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • CuO nanoparticles are successfully synthesized using green approach. • The energy band-gap was calculated to be 1.92 (papaya peel extract), and 1.22 eV (banana peel extract), respectively. • The degradation of MB is facilitated using CuO NPs under visible light. • Pseudo-first-order kinetics describes the degradation reaction satisfactorily. Copper Oxide (CuO) nanoparticles were synthesized through a green approach using the papaya and banana peel reducing as well as a stabilizing agents and copper (II) nitrate trihydrate salt as a precursor. The sample was characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), Scanning electron microscope (SEM), Transmission electron microscope (TEM), and UV–visible diffuse reflectance spectroscopy (DRS). The characterization results revealed about the CuO NPs structure, shape, energy gap, and functional group variations. The energy band-gap was calculated to be 1.92 (papaya peel extract), and 1.22 eV (banana peel extract), respectively. Under visible light irradiation, the photocatalytic activity of CuO NPs was investigated by degrading Methylene blue (MB) dye. It depicts that synthesized CuO NPs have a great potential for application as a photocatalyst to degrade textile colours in wastewater treatment in a short period. Moreover, the pseudo-first-order reaction rate constants were found to be 0.00359 min−1 (papaya peel extract) and 0.00335 min−1 (banana peel extract), respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • Non noble Copper oxide (CuO) NPs is synthesized with controlled size by quercetin mediated hydrothermal method. • The material is applied as heterogeneous catalyst for 'Click' Synthesis of 1, 2, 3-Trizoles. • The use of hazardous organic azides were avoided. • Quick formation of product was observed with excellent yields under mild reaction conditions. • The catalyst is recyclable, reusable and environmental friendly. 'Quercetin' a simplest flavanoid possessing five hydroxyl groups, is employed as a capping agent in CuO nanoparticles preparation with the help of hydrothermal autoclave. The CuO nanoparticles acted as an efficient and cost effective catalyst for 'click' synthesis of 1,4-disubstituted 1,2,3-triazoles. The physical and chemical properties of the prepared catalyst were characterized by various techniques such as, Fourier-transform infra red (FTIR), Simultaneous thermal analysis (STA or TG-DTA), Powder X-ray diffraction (P-XRD), Scanning electron microscope (SEM), Transmission electron microscope (HR-TEM) analysis and surface area analyzer BET (Brunauer-Emmett-Teller). The CuO nanoparticles prepared with quercetin were found to possess smaller size. The catalytic reaction was carried out under mild conditions and the yield of the products was reasonable. Even up to 6 catalytic cycles the CuO nanoparticles could give considerable yield of triazoles products. [ABSTRACT FROM AUTHOR]

• Fe, Co, and Ni doped MnO x was grown on NG. • Doped catalysts show better ORR activity than the undoped one. • Doping can tune the Mn valence. • Enhanced activity for doped MnO x owing to increase in Mn valence on doping. We report the electrochemical activity of transition metal ion (Fe, Co and Ni) doped MnO x @ N -graphene (MnO x @NG) hybrid catalysts towards oxygen reduction reaction (ORR). The doped catalysts displayed significantly enhanced electrochemical performance than the undoped one. The Fe doped MnO x @NG exhibited highest positive shift in onset potential (0.93 V vs. RHE), highest electron transfer number (n) (3.87) and lowest peroxide yield (6.35 %) in 0.1 M KOH solution. The Co doped catalyst showed highest current density, which is comparable to that of benchmark 20 wt% Pt/C. The XRD analysis showed that the catalyst samples are poorly crystalline and the doping of either Fe or Co or Ni cation induces formation of Mn 2 O 3 , whereas the undoped catalyst consists of both Mn 2 O 3 and MnOOH. The STEM (scanning transmission electron microscope) micrographs revealed that in all the samples the MnO x nanostructures are well dispersed on NG and the elemental mapping of the doped catalysts showed uniform distribution of dopants. The X-ray photoelectron spectroscopy (XPS) studies revealed that doping of either cation results an increase in the average Mn valency of the host MnO x. The change in crystal structure and corresponding ORR activity has also been investigated with increase in dopant amount for Fe doped samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • Trimetallic nanoparticles were incorporated onto SiO 2 matrix. • Facile microwave reduction method was used. • Adsorption of Methylene blue (MB) dye was carried out. • The maximum adsorption capacity for MB dye was 294.11 mg/g. • Reusability study carried out for six consecutive cycles. The removal of toxic dyes from the wastewater is a serious concern. One of the commonly employed dyes in the textile industry is methylene blue (MB). Its presence in water not only reduces the aesthetic value of the water but also affects aquatic life. Considering this, we have worked on the designing of Bi 2 O 3 -SrO-FeO@SiO 2 nanocomposite using a simple microwave irradiation method. The synthesized Bi 2 O 3 -SrO-FeO@SiO 2 nanocomposite was characterized by various techniques such as scanning electron microscope, transmission electron microscope, X-Ray diffractometer, elemental mapping, Energy- dispersive X-Ray, and X-ray photoelectron spectrophotometer. The adsorption technique was utilized for the effective removal of MB using Bi 2 O 3 -SrO-FeO@SiO 2 nanocomposite. Effects of various factors such as the concentration of MB, amount of Bi 2 O 3 -SrO-FeO@SiO 2 nanocomposite, and reaction time were undertaken for getting some optimized parameters for the further experiments. Adsorption isotherm models such as Langmuir, Freundlich, and Temkin were employed for the adsorption data. Besides, adsorption kinetic models such as Pseudo- first order and Pseudo- second-order were also studied for determining the rate of the undertaken adsorption process. At last, the reusability of the Bi 2 O 3 -SrO-FeO@SiO 2 nanocomposite was studied for six consecutive cycles for elaborating the practical application of the synthesized adsorbent. [ABSTRACT FROM AUTHOR]

Ag+ ions incorporated MgS nanoparticles were synthesized by the co-precipitation method. X-ray diffraction (XRD) spectra revealed that the samples had a cubic structure and the transmission electron microscope (TEM) pictures confirmed the spherical shape and size of the particle. The particle size was ranged from 11 nm to 15 nm. The average size of the particles was decreased for the increase of Ag+ ions concentration. Scanning Electron Microscope (SEM) photographs disclosed the surface morphology of samples. The agglomeration of the samples was reduced in the higher doping concentration. Energy Dispersive X-ray (EDX) and Fourier Transform Infrared (FTIR) analysis were utilized to verify the presence of elements as per the stoichiometry ratio. UV–vis absorption was increased due to the incorporation of Ag+ ions and better transmittance was offered for Ag = at. 2 %. The optical band gap was blue-shifted for Ag+ ions incorporated MgS nanoparticles. High intense strong red photoluminescence (PL) emission was exhibited at 660 nm by MgS:Ag for Ag = 2 at.%. The shifting of PL peaks to higher wavelength indicates the Ag+ ions incorporation. The shallow donor defects produced PL emission in a strong red region. The red emission may also be ascribed to the electron transition in high energy levels. [ABSTRACT FROM AUTHOR]