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Herein, the change in the growth characteristics of nickel (Ni)–graphite core–shell nanoparticles (CSNP) based on growth time using thermal chemical vapor deposition method and its utilization in silver (Ag) paste is presented. The characteristics of the graphite shell formed on the surface of Ni–graphite CSNPs exhibited changes in structure, crystallinity, and thickness depending on the growth time. Changes in the characteristics of the graphite shell caused changes in the electrical characteristics of Ni–graphite CSNPs. Ni–graphite CSNPs synthesized based on growth time were able to present synthesis conditions with the most similar characteristics to Ag powder through electrical characteristic evaluation. In addition, through the commercialized Ag paste process, it was suggested that some of the Ag powder could be replaced with Ni–graphite CSNPs and utilized. Through this approach, a plan to improve the price competitiveness of expensive Ag paste was proposed. [ABSTRACT FROM AUTHOR]

We present the combustion-based synthesis of BiFeO3 (BFO) and Gd:BiFeO3 perovskite nanoparticles. XRD analysis demonstrates that the undoped BFO (x = 0) perovskite sample shows a single perovskite phase with a rhombohedral structure. However, increase in the Gd3+ content from x = 0.05 and 0.15 to 0.25 led to the occurrence of a structural phase transformation from rhombohedral (BiFeO3) to orthorhombic (Bi2Fe4O9). With an increase in the Gd-dopant the average crystallite size of rhombohedral structures increased from 16 to 23 nm. The perovskite samples were examined using XPS, which confirmed the presence of Bi3+, Gd3+, Fe2+, and O2+ ions. FT-IR spectroscopy indicated the existence of elemental functional groups in the synthesized perovskite nanoparticles. Furthermore, the direct band gap measured by DRS reduced from 2.16 to 2.0 eV as the Gd concentration increased. The nanoparticles of the BFO perovskite had an uneven shape, a tendency to agglomerate, and fused grains with defined grain boundaries. At ambient temperature, both the undoped and Gd:BFO perovskite nanoparticles exhibit a ferromagnetic characteristic. It was found that the BET surface area of the undoped and Gd-doped BFO perovskite nanoparticles varied progressively from 4.38 to 33.52 m2 g−1. The catalytic oxidation studies conducted in a batch reactor under air conditions revealed that the synthesized catalysts, in particular, Gd:BFO (x = 0.25), exhibited higher conversion and selectivity efficiencies for glycerol (con. 100% and sel. 99.5%, respectively). [ABSTRACT FROM AUTHOR]

Utilizing microwave combustion method Co3-xCuxO4 (x = 0 and 0.5) nanoparticles were prepared utilizing l-alanine as fuel. The phase and crystal structure of Co3O4 and Cu: Co3O4 nanoparticles are studied employing X-ray diffraction technique, which further ensured the phase formation and crystallite size was determined. The crystallite size was observed to be 27.39 and 39.22 nm respectively for pure and Cu:Co3O4 nanoparticles respectively. HRSEM images of the prepared samples unveiled spherical morphology. The presence of Cu, Co and O is observed through Energy dispersive X-ray spectra. Optical bandgap values were assessed and they were observed to lie within 2.87–2.97 eV. FT-IR spectra peaks at 573 and 664 cm−1 were responsible for Co3+ of octahedral sites besides Co2+ of tetrahedral sites respectively. The M-H loops exhibited super paramagnetic behaviour. Furthermore, we have investigated the various concentrations of Co1-xCuxO (x = 0 and 0.5) nanoparticles towards potential cytotoxicity effect against the A549 human lung epithelial cancer cell lines. [ABSTRACT FROM AUTHOR]

We present a simplistic, ultrafast, and facile hydrothermal deposition of ternary Cu2SnS3 nanoparticles (CTS NPs). The fabricated CTS NPs show superior antimicrobial and photocatalytic activities. In the presence of UV-Visible illumination, methylene blue (MB) dye was studied for photocatalytic dye degradation activity of CTS NPs. Excellent efficiency is shown by incorporating CTS NPs to degrade MB dye. There is a ~95% decrease in the absorbance peak of the dye solution within 120 min. Similarly, CTS NPs tested against three bacterial strains, i.e., B. subtilis, S. aureus, P. vulgaris, and one fungal strain C. albicans, defining the lowest inhibitory concentration and zone of inhibition, revealed greater antimicrobial activity. Hence, it is concluded that the CTS NPs are photocatalytically and antimicrobially active and have potential in biomedicine. [ABSTRACT FROM AUTHOR]

Ferrites have been broadly investigated as gas sensors. The present article reports on the synthesis of Co-ferrite doped with W ions and their gas sensing abilities. A series of single phase CoFe2O4 powder with different W-doping (0.0 ≤ x ≤ 0.15) was synthesized using sol-gel synthesis. A variation in the saturation magnetization (Ms) and the lattice dimension with W(VI) substitution was associated with a change in the distribution of Fe(III) ions between tetrahedral and octahedral sites. Introducing W(VI) ions into the spinel lattice induced the rearrangement of Fe(III) ions. The total Ms increased with W-doping up to x = 0.05 (Ms = 50.1 Am2/kg) and it dramatically decreased to 34.6 Am2/kg with x = 0.15 of doping. However, the lattice parameter increased with increasing doping levels. Different W-doped CoFe2O4 were examined for a gas sensing response in the temperature range of 200–450 °C. Comparing the sensor responses to various reducing gases, the material's response was shown to be sensitive and selective for acetone. The addition of W (0.15%) had a significant impact on the response and on the operating temperature of the sensor material, indicating that it might be used as an acetone sensor. [ABSTRACT FROM AUTHOR]

A core–shell photoanode, composed of a monoclinic WO3 nanorods core encapsulated with a rutile TiO2 nanoparticles shell, reveals ∼246% enhancement in power conversion efficiency due to improved current density and open circuit voltage values and longer-lived charge carriers. [ABSTRACT FROM AUTHOR]

One-step and template-free synthesis of polyaniline nanobuds (PANI NBs), synthesized using anodic electrochemical polymerization method, is reported at room temperature onto a conducting indium-tin-oxide glass substrate. The PANI NBs are characterized for their structural, morphological, and electrochromic properties. Scanning electron microscopy image reveals NBs type architecture, perpendicular to the substrate surface. These NBs are broader at their bottoms and narrower at the tops. Individual NB has confirmed 30 nm top diameter and 100-200 nm length. Electrochemical supercapacitive behavior of the PANI NBs electrode is investigated by measuring cyclic voltammetry curves. Moderate specific capacitance of 128 F/g is achieved in the potential range of −0.2 to 1.0 V at 10 mV/s sweep rate in 0.5 M H2SO4 electrolyte. Influence of inner and outer charges on a resultant specific capacitance is also investigated. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

Co 0.5 Ni 0.5-x Sr x Fe 2 O 4 powders with x values of 0.1, 0.2, 0.3, 0.4 and 0.5 were quickly produced using the Solution Combustion Synthesis (S.C.S.) method. The effects of strontium (Sr) concentrations on the structure, microstructure, and magnetic properties were investigated using a variety of characterization methods. The SC technique produced single-phase spinel ferrites with a space group of Fd-3m (JCPDS data: 01-074-5694) directly and did not require any additional heat treatment throughout the manufacturing process. The lattice parameter increased due to the addition of the Sr ions, but the redistribution of the various cations resulted in a drop in the fraction of the Fe3+ cations found in the (A) sites. The average crystallite size reduced from 23 to 19 nm. Scanning Electron Microscopy (S.E.M.) displays well-shaped spherical grains in the nanoscale region, but larger grains with agglomeration were discovered with Sr doping of spinel ferrite nanoparticles. Room temperature Mössbauer spectra have a structure typical for superparamagnetic nanoparticles. To determine the distributions of iron ions at the A- and B- sites, the low-temperature measurements of Mössbauer spectra were performed at 15K, where the effect of relaxation on the structure of Mössbauer spectra is negotiable, the concentration of iron ions in A- and B-site were determined. It has been established that the substitution of Nickel ions for Strontium ions leads to the growth of F e A 3 + / F e B 3 + ratio from 0.75 to 0.89. In this study, we show the effect of Sr doping on the structure, morphology and magnetic properties Co–Ni ferrite nanoparticles, which are suitable for a wide variety of applications because of their adaptability. [ABSTRACT FROM AUTHOR]

The degradation of organic dyes in wastewater has become a significant environmental issue, requiring the development of degradation technologies that are both effective and environmentally friendly. The present study employed the sol-gel approach to synthesize nanoparticles of phase pure bismuth ferrite (BiFeO 3). The nanoparticles were assessed for their ability to efficiently degrade methylene blue (MB) dye, especially under visible light irradiation. The X-ray diffractogram (XRD) confirmed the formation of BiFeO 3 nanoparticles, with an average crystallite size of 48 nm. The material's band gap, with a value of 1.84 eV, demonstrates its capacity to effectively absorb light, including wavelengths within the visible spectrum. Scanning electron microscopy (SEM) was used to identify porous aggregated particles. Both Raman and Fourier transform infrared spectroscopy (FTIR) confirm the successful synthesis of pure BiFeO 3 in the desired phase. The BiFeO 3 photocatalyst exhibited a significant surface area and isotherms of type IV, a characteristic typically observed in mesoporous materials, as determined by the Brunauer-Emmett-Teller (BET) analysis. The efficacy of BiFeO 3 nanoparticles in facilitating the decomposition of MB in a water-based solution was evaluated by visible light photocatalysis. An efficiency degradation of 98.49 % was recorded for MB within 2 h. [Display omitted] • Sol-gel method to synthesis of very pure BiFeO 3 nanoparticles. • Photocatalytic activities of BiFeO 3 for degradation of MB under visible light irradiation. • Low 1.84 eV band gap energy absorb light even in the visible spectrum. • Large surface area and isotherms of type IV, a typical characteristic of mesoporous materials. • Degradation efficiency for MB was found to be 98.49 %. [ABSTRACT FROM AUTHOR]

• WC@GNFs nanocomposites were applied in capacitive deionization. • 10%WC@GNFs displayed the smallest pore size and increased pore volume among the prepared nanocomposites. • Introducing WC in WC@GNFs nanocomposites appreciably reduced their charge transfer resistances. • Increased electrosorptive capacity of 22.155 mg g−1 was measured for 10%WC@GNFs in 300 μS cm−1 NaCl solution. In this present work, tungsten carbide (WC) nanoparticles were intercalated between graphene nanoflakes (GNFs) using sonication followed by hydrothermal treatment. Pristine WC, GNFs and a series of WC@GNFs nanomaterials were physically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) and water contact angle measurements. Cyclic voltammetry and electrochemical impedance studies were operated to investigate the electrochemical performance of these nanocomposites as efficient capacitive deionization (CDI) electrodes with improved electrochemical characteristics and specific capacitances in NaCl solution. Among the synthesized nanomaterials, WC@GNFs containing 10% WC displayed appreciable specific capacitance [580.00 F g−1], salt removal efficiency [95.50%], electrosorptive capacity [22.155 mg g−1] and charge efficiency [0.356] values. Accordingly, the measured results in this study indicate that WC@GNFs nanomaterials are suitable electrodes with an easy preparation route for efficient CDI technology. [ABSTRACT FROM AUTHOR]