Addition Of SnO2 Nanoparticles Research Articles

Enhancements of critical current density in Bi1.6Pb0.4Sr2Ca2Cu3O10+δ superconductors by additions of SnO2 nanoparticles

The impact of adding SnO2 nanoparticles on the enhancements of critical current density (Jc) of the Bi1.6Pb0.4Sr2Ca2Cu3O10+δ superconductors was studied. Polycrystalline superconductors with stoichiometry of (Bi1.6Pb0.4Sr2Ca2Cu3O10+δ)1−x(SnO2)x where was x was ranged from 0.000, 0.002, 0.004, 0.006, 0.008 to 0.010 were made through traditional solid state reaction technique. X-ray diffraction data revealed that all fabricated samples consisted of Bi-2223 and Bi-2212 superconducting phases. The volume fraction of the Bi-2223 phase decreased with SnO2 addition. Analyses of textural structure using scanning electron microscopy data evidenced a clear decrease in grain orientation and porosity with increased doping levels. SnO2 presence in connection to Bi-2223 deceleration reduced the critical temperature. Values of Jc deduced from the magnetization hysteresis loops measured at different temperatures of 35 K, 45 K, 55 K, 65 K were found to enhance for the SnO2 added samples. In the x = 0.002 samples, the field dependent Jc achieved its maximum values. In order to have a deeper understanding in the improvements of flux pinning properties, small and large bundle fields were determined by using the collective pinning theory. The obtained values indicate the expansion of the two corresponding regimes with appropriate. By analyzing the dependence of normalized Jc versus normalized critical temperature, the dominant flux pinning mechanisms in all samples were consistent with δl pinning. Besides, the addition of SnO2 nanoparticles was likely to produce pinning centers in form of core point as evidenced by using the Dew–Hughes model.

Phase Formation and Conductivity Fluctuation Investigation in Nanoparticle SnO2-Added Y3Ba5Cu8O18 ± δ Polycrystalline Superconductor

The influence of 0, 0.20, 0.40, 0.50, and 0.60 wt % nano-sized tin oxide (SnO2) particles on electrical conductivity fluctuation in normal and superconducting state of the Y3Ba5Cu8O18 ± δ (denoted as Y‑358) polycrystalline samples is studied. Phase formation and microstructures have been systematically examined. By increasing the content of SnO2 in YBCO matrix, X-ray diffraction technique showed slight variation in lattice parameters and overall reduction in the orthorhombicity. Scanning electron microscopy observations and the crystallite size calculation also revealed that the grain size and the average crystallite size decreased compared to the SnO2-free sample. Aslamazov–Larkin and Lawrence–Doniach prototypes were used to analyze conductivity fluctuations based on the electrical resistivity ρ(T) measurements. Superconducting transition temperatures TC and TLD have been reported. The influence of SnO2 addition on the superconducting properties indicates that with the addition of SnO2 nanoparticles into Y-358 compound, some parameters values such as zero-resistance critical temperature TC zero, coherence distance alongside the c axis at 0 K ξc(0), and super-layer length d decrease in total, while anisotropy γ, critical magnetic fields Bc1(0), Bc2(0), and critical current density Jc(0) increase in SnO2-added Y-358 specimens compared to the pure one. The reasons corresponding to these scenarios are discussed in details.

Preparation of novel polyvinylidene fluoride (PVDF)-Tin(IV) oxide (SnO2) ion exchange mixed matrix membranes for the removal of heavy metals from aqueous solutions

Global consideration has been growing recently to tackle the toxic and carcinogenic effects of heavy metal presence in water streams. In this work, novel polyvinylidene fluoride (PVDF)/tin(IV) oxide (SnO2) ion exchange membranes were prepared via the phase inversion method and their performance and properties were analyzed. The results showed that the addition of SnO2 nanoparticles (SnNPs) led to an improvement in the pure water flux from 25.5 ± 1.5 L/m2.h in the pristine PVDF membrane to 250.5 ± 12.5 L/m2·h in the 1.00 wt% PVDF/SnNPs membranes. This was related to the increase in the overall porosity and hydrophilicity of the membranes. Additionally, the 0.25 wt% PVDF/SnNPs membrane reported the highest tensile strength equal to 21.3 ± 0.6 MPa compared to only 14.3 ± 0.4 MPa in the pristine PVDF membrane. Lastly, the maximum removal of Pb2+, Cu2+, Zn2+, Cd2+, and Ni2+ was achieved by the 0.25 wt% PVDF/SnNPs membrane with around 93.9 ± 1.7, 92.8 ± 1.3, 82.3 ± 2.0, 70.7 ± 1.1, and 63.9 ± 1.5%, respectively, compared to 93.5 ± 1.3, 92.9 ± 1.7, 68.3 ± 2.1, 50.3 ± 1.8, and 50.3 ± 1.4% in the pristine PVDF membrane. The mechanism of removal was predicted to be a combination of ion exchange/adsorption, inner-sphere complexations and electrostatic attraction between the metal ions and the SnNPs. Such a PVDF/SnNPs membranes have great potential in the field of wastewater treatment.

Дифференциальная термоЭДС углеродных нанотрубок типа "zigzag" во внешнем электрическом поле

The influence of (0.00, 0.20, 0.40, 0.50, and 0.60wt%) nano-sized tin oxide (SnO2) particles on electrical conductivity fluctuation in normal and superconducting state of the Y3Ba5Cu8O18±δ (denoted as Y-358) polycrystalline samples is studied. Phase formation and microstructures have been systematically examined. By increasing the content of SnO2 in YBCO matrix, X-ray diffraction technique showed slightly variation in lattice parameters and overall reduction in the orthorhombicity. Scanning electron microscopy observations and the crystallite size calculation also revealed that the grain size and the average crystallite size decreased compared to the SnO2 free sample. Aslamazov–Larkin and Lawrence–Doniach prototypes were performed to analyse conductivity fluctuations based on the electrical resistivity ρ(T) measurements. Superconducting transition temperatures Tc and TLD have been reported. The influence of SnO2 addition on the superconducting properties indicates that with the addition of SnO2 nanoparticles into Y-358 compound, some parameters values such as zero-resistance critical temperature Tc zero, coherence distance alongside the c axis at 0K ξc(0), and super-layer length d decrease in total, while anisotropy γ, critical magnetic fields Bc1(0), Bc2(0), and critical current density Jc(0) increase in SnO2-added Y-358 specimens compared to the pure one. The reasons corresponding to these scenarios are discussed in details.

A comparative study on the influence of the addition of different nano-oxide particles on the thermopower of (Bi,Pb)-2223 superconductor

Solid-state reaction technique was used to prepare superconductor samples with nominal composition of (SnO2)x(Bi,Pb)-2223 and (NiO)x(Bi,Pb)-2223, where 0.0 ≤ x ≤ 0.2 wt%. The prepared samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The impact of SnO2 and NiO nanoparticles addition on the thermopower of (Bi,Pb)-2223 was measured using a standard differential technique. The Seebeck coefficient values in the presence of NiO nanoparticles were about 5–37.9% higher than those obtained with the addition of SnO2 nanoparticles. Higher values of Seebeck coefficients result in a wide variety of applications of these superconductors such as electronics and thermoelectric devices. The obtained results were analyzed according to the two-band model (Fermi-liquid model) and the two-band model with an extra linear term. The Fermi velocity (υF), Fermi energy, Fermi temperature (TF), Fermi wavenumber (KF), Fermi wavelength (λF) as well as the carrier concentration (N/V) values were calculated and discussed as a function of the nanoparticles content.

One-step hydrothermal synthesis and characterisation of SnO2 nanoparticle-loaded TiO2 nanotubes with high photocatalytic performance under sunlight

The enhancement of the photocatalytic activity of TiO2 nanotubes (TNTs), as a result of heterojunction formation through the addition of SnO2 nanoparticles (NPs) by a simple and straightforward one-step hydrothermal method, is shown. The structure and properties of the as-synthesised composite material are characterised using X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, UV–Vis diffuse reflectance spectroscopy, Raman spectroscopy and photoluminescence spectroscopy. The SnO2/TNT heterojunction with extremely small SnO2 NPs adhered on the TNT surface was successfully synthesised by a one-step hydrothermal synthesis. The mechanism and factors affecting the photocatalytic activity were verified and clarified. Furthermore, the sample with 2% SnO2 precursor content has the highest photocatalytic activity with a methylene blue degradation efficiency of 74.2% for 180 min under sunlight irradiation.

Role of SnO2 nanoparticles on mechanical and thermal properties of flexible polyurethane foam nanocomposite

Neat polyurethane (PU) foams and polyurethane/nano tin oxide composites were prepared using in situ polymerization, blending methods. The produced nanocomposites were investigated by scanning electron microscopy, Fourier transform infrared spectra, thermal gravimetric analysis (TGA), and compression test. It was found that modification of tin oxide particles caused to make better distribution in PU foam nanocomposites. The results showed that increasing isocyanate content leading to enhance cross-link, density and compression strength of neat PU foams. Addition of SnO2 nanoparticles in different density of PU foam showed variety effects. In low density foam increasing amount of SnO2 nanoparticles from 0.5 to 1 wt% leaded PU foam to become soft with low strength. Moreover, TGA results of all PU foams exhibited one thermal decomposition step. Also, increasing isocyanate ratio and SnO2 nanoparticles improved thermal stability of PU foams.

SnO2 nanoparticles-reduced graphene oxide nanocomposites for NO2 sensing at low operating temperature

SnO2 nanoparticles-reduced graphene oxide (SnO2-rGO) nanocomposites have been successfully prepared by a facile method via hydrothermal treatment of aqueous dispersion of GO in the presence of Sn salts. The combined characterizations including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) indicate the successful formation of SnO2-rGO nanocomposites. To demonstrate the product on sensing application, gas sensors are fabricated using SnO2-rGO nanocomposites as sensing materials and investigated for detection of NO2 at low operating temperature (50°C). It is found that SnO2-rGO nanocomposites exhibit high response of 3.31 at 5ppm NO2, which is much higher than that of rGO (1.13), and rapid response, good selectivity and reproducibility. Furthermore, the reason for enhancing sensing performance by addition of SnO2 nanoparticles has also been discussed.

Influence of the addition of SnO 2 nano-particles on Bi-2223 phase formation.

The effect of the addition of SnO2 nano-particles on Bi-2223 phase formation has been studied. Tin oxide was added at different intervals of the synthesis process. It is shown that the addition of SnO2 inhibits the Bi-2223 phase formation regardless of when it is introduced to the system. SnO2 partially reacts with calcium to form the Ca2SnO4 phase. This phase is stable throughout the synthesis process. As a consequence, the formation of the Bi-2223 phase is compromised for the benefit of secondary phases such as Bi-2212, Ca2SnO4, Sr0.15Ca0.85CuO2 and Cu2SrO2. The c parameter of the Bi-2223 phase increases when tin is added. A possible explanation is a partial substitution of Cu2+ by Sn4+.