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The present paper describes photocatalytically active In2O3 thin films developed using a direct drop-cast method on F-doped tin oxide (FTO) coated glass substrates using 10 mM In(NO3)3 dissolved in ethylene glycol containing 0–0.0125 M Triton-X 100 (TX-100) surfactant and annealed in air at 600 °C to obtain the desired metal oxide. The absorption spectrum measured the direct band gap of the surfactant modified In2O3 as 3.48 eV along with an indirect gap of 2.69 eV indicating near visible absorptivity of the materials, which was established through linear sweep voltammetry under periodic UV-Vis and visible irradiation for oxidation of water and a sacrificial reagent, SO32−. The electrochemical impedance spectroscopic (Mott–Schottky) analysis confirms n-type semiconductivity for these materials. Addition of an optimized level of 0.01 M TX-100 surfactant to the precursor solution improves the photoelectrochemical performance of the film to 2.3 fold. The electrochemical action spectra indicate a maximum value of the incident photon to current conversion efficiency (IPCE) for the 0.01 M surfactant modified In2O3 of 28% and the corresponding absorbed photon to current conversion efficiency (APCE) of 40%. Addition of surfactant to the In3+ precursor solution results in uniformly distributed particle growth on the surface with better crystallinity. [ABSTRACT FROM AUTHOR]

Niobium carbide (NbC) nanoparticles embedded on the surface of carbon spheres (CS) were synthesized at 1350 °C by the carbothermal reduction of niobium oxide precursor in flowing argon (Nbc@CS). The morphology, crystal structure, and magnetic properties of the hybrid nanocomposite were investigated by means of electron microscopy, X-ray diffraction and a superconducting quantum interference device. It was found that the NbC@CS nanocomposites exhibit type-II superconductivity with a critical temperature (Tc) of 8–12 K, typical for stoichiometric NbC. The superconducting hysteresis loop reveals several interesting traits, including strong vortex pinning, the presence of asymmetry and a high penetration field. Moreover, the sample shows much improved irreversible (Hirr), lower (Hc1) and upper (Hc2) critical fields. The coherence length (ξ), penetration depth (λ), and Ginzburg–Landau (κ) parameters for the sample were estimated to be 9.78 nm, 33 nm and 3.39, respectively. [ABSTRACT FROM AUTHOR]

The decoration of carbon spheres (CS) by highly dispersed tantalum carbide nanoparticles (TaC NPs) was achieved, for the first time by a unique carbothermal reduction method at 1350 °C for 30 min under reduced oxygen partial pressure. TaC NPs decorated CS composites were then extensively characterized by powder X-ray diffraction and electron microscopy techniques. The composite spheres were approximately 0.8–1 μm in diameter with an average size of 41 nm for the TaC NPs located at the surface. Transmission electron microscopy and Raman analysis showed the formation of the graphene layer at the outer surface of the TaC NPs. An anomalous ferromagnetic response with a spin-glass like behavior has been observed at low temperature in the dc magnetization study with complete suppression of the superconducting response. For ease of synthesis and high reproducibility, this technique opens a new paradigm in the preparation of carbon sphere supported high melting metal carbide nanoparticles for various technological purposes. [ABSTRACT FROM AUTHOR]

Polypyrrole (PPy)–coated magnetite (Fe3O4) hybrid particles were synthesized under sonication. PPy was coated on the surface of Fe3O4 microspheres, whereas pyrrole monomers filled the interior of the Fe3O4 particles and were then polymerized. The structure of the Fe3O4–PPy microspheres was confirmed by transmission electron microscopy. The electric and magnetic properties were confirmed by optical microscopy and vibrating sample magnetometry, respectively. The suspension of the Fe3O4–PPy composite microspheres dispersed in silicone oil exhibited both electrorheological and magnetorheological properties when measured using a rotational rheometer under an applied electric and magnetic field, respectively. [ABSTRACT FROM AUTHOR]

Fe0 nanoparticle-supported polyaniline (PANI) composite nanofibers were prepared as an additive for carbonyl iron (CI)-based magnetorheological (MR) fluids to improve the MR properties and dispersion stability. A simple chemical strategy was adopted to synthesize the PANI/Fe0 composite nanofibers. The synthesis method was based on the initial fabrication of interconnected PANI nanofibers by a rapidly mixed polymerization process using ferric chloride (FeCl3) as the oxidant and the subsequent reductive support of Fe0 nanoparticles onto the PANI nanofiber matrix using the polymerization by-products as a metal precursor. X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy showed that the fabricated nanofibers were composed of PANI and Fe0. Scanning and transmission electron microscopy imaging confirmed that the PANI/Fe0 composite nanofibers were 80–150 nm in diameter with an interconnected matrix. The MR fluid with the PANI/Fe0 composite nanofibers dispersed in mineral oil under an external magnetic field showed enhanced MR properties compared to that without an additive. Turbiscan data also confirmed the improved sedimentation properties of the MR fluid with an additive. [ABSTRACT FROM AUTHOR]