Growth of catalyst-free high-quality ZnO nanowires by thermal evaporation under air ambient

ZnO nanowires have been successfully fabricated on Si substrate by simple thermal evaporation of Zn powder under air ambient without any catalyst. Morphology and structure analyses indicated that ZnO nanowires had high purity and perfect crystallinity. The diameter of ZnO nanowires was 40 to 100 nm, and the length was about several tens of micrometers. The prepared ZnO nanowires exhibited a hexagonal wurtzite crystal structure. The growth of the ZnO nanostructure was explained by the vapor-solid mechanism. The simplicity, low cost and fewer necessary apparatuses of the process would suit the high-throughput fabrication of ZnO nanowires. The ZnO nanowires fabricated on Si substrate are compatible with state-of-the-art semiconductor industry. They are expected to have potential applications in functional nanodevices

Hydroxyapatite Mineralization on the Calcium Chloride Blended Polyurethane Nanofiber via Biomimetic Method

Polyurethane nanofibers containing calcium chloride (CaCl2) were prepared via an electrospinning technique for the biomedical applications. Polyurethane nanofibers with different concentration of CaCl2 were electrospun, and their bioactivity evaluation was conducted by incubating in biomimetic simulated body fluid (SBF) solution. The morphology, structure and thermal properties of the polyurethane/CaCl2 composite nanofibers were characterized by means of scanning electron microscopy (SEM), field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetry. SEM images revealed that the CaCl2 salt incorporated homogeneously to form well-oriented nanofibers with smooth surface and uniform diameters along their lengths. The SBF incubation test confirmed the formation of apatite-like materials, exhibiting enhanced bioactive behavior of the polyurethane/CaCl2 composite nanofibers. This study demonstrated that the electrospun polyurethane containing CaCl2 composite nanofibers enhanced the in vitro bioactivity and supports the growth of apatite-like materials

Mechanical Deformation Behavior of Nonpolar GaN Thick Films by Berkovich Nanoindentation

In this study, the deformation mechanisms of nonpolar GaN thick films grown on m-sapphire by hydride vapor phase epitaxy (HVPE) are investigated using nanoindentation with a Berkovich indenter, cathodoluminescence (CL), and Raman microscopy. Results show that nonpolar GaN is more susceptible to plastic deformation and has lower hardness thanc-plane GaN. After indentation, lateral cracks emerge on the nonpolar GaN surface and preferentially propagate parallel to the orientation due to anisotropic defect-related stresses. Moreover, the quenching of CL luminescence can be observed to extend exclusively out from the center of the indentations along the orientation, a trend which is consistent with the evolution of cracks. The recrystallization process happens in the indented regions for the load of 500 mN. Raman area mapping indicates that the distribution of strain field coincides well with the profile of defect-expanded dark regions, while the enhanced compressive stress mainly concentrates in the facets of the indentation

Ternary metal oxide of CuNiCo2O4nanorods (1D) distributed on g-C3N4 (2D) nanocomposite for non-enzymatic glucose sensing application

Non-enzymatic glucose sensing has a major demand in research community for developing a good glucose sensor. Because enzyme based glucose sensor has several disadvantages such as high cost, difficult fabrication process and instability. To overcome these disadvantages, transition metal oxides (TMO) with g-C3N4 nanocomposite are a good choice for non-enzymatic medium for developing a good glucose sensor. Transition metal oxide has multiple oxidation state, different morphology, high conductivity, enhanced catalytic activity and 2D graphitic carbon nitride has a higher stability. In this work, our particular interest in ternary metal oxide (CuNiCo2O4) nanorods (1D) distributed on surface of the g-C3N4 (2D) nanocomposite were prepared by simple hydrothermal method. The prepared nanocomposite was performed a basic studies such as XRD, FESEM, HRTEM, FTIR, XPS and an electrochemical studies using nickel foam as a current collector. Chronoampermetry analysis produced a sensitivity of 4368 μA Cm−2 mM−1 and low detection limit (LOD) 1.91 μM. The produced response time is 4 s. The measured results of the CuNiCo2O4nanorods (1D) on the surface of g-C3N4 (2D) nanocomposite could be a satisfied material for non-enzymatic glucose sensor

One-Step Hydrothermal Synthesis of Cobalt Sulfide/E-Waste Derived Activated Carbon Nanocomposite as a Bifunctional Electrocatalyst for Overall Water-Splitting

An electrocatalyst with high performance can enhance the hydrogen production for overall water-splitting. This study reports on the e-waste-derived activated carbon encapsulated cobalt sulfide (CoS2/AC) nanocomposite synthesized via a simple hydrothermal process for overall water-splitting application. The microstructural image of CoS2/AC showed the aggregated stacked nanosheets of activated carbon encapsulating the cobalt sulfide nanoparticles. The nanocomposite of CoS2/AC exhibited the overpotential of 240 mV at 10 mA cm−2 and a 34 mV dec−1 of Tafel slope value with extraordinary stability for OER. On the other hand, the nanocomposite exhibited the overpotential of 378 mV at 10 mA cm−2 with a Tafel slope of ∼134 mV dec−1 with splendid stability in 1 M KOH solution for HER. The enhanced electrical conductivity and electrochemically active surface area of the AC nanosheets and CoS2 nanoparticles in this nanocomposite account for its higher electrocatalytic activity. Thus, the hydrothermally synthesized CoS2/AC presents itself as a better bifunctional catalyst for overall water-splitting.</jats:p

Hydrogen incorporation effect in phosphorus-doped p-type ZnO thin films grown by radio-frequency magnetron sputtering

We report on the influence of hydrogen incorporation on the conductivity of phosphorous (P) doped ZnO thin films grown by using radio-frequency (RF) magnetron sputtering.</p