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Tin oxide (SnO2) nanoparticles were prepared by green synthesis process using extract of leaf from buckthorn and tin (IV) chloride pentahydrate (SnCl4·5H2O). The materials calcined at 400 °C for 3 h to produce of SnO2 NPs. SnO2 nanoparticles were characterized by X-ray diffraction, scanning electron microscope, optical microscope, and optical spectroscopy techniques.The result of XRD showed formation tin oxide nanoparticles with tetragonal crystal structure. The optical properties were enhanced with rising concentration from 1.25gm/100 ml to 5gm/100 ml. The optical absorbance (A) enhanced of 42.3% at λ = 340 nm (UV-spectrum), 55.8% at λ = 540 nm (VIS-spectrum) and 53.3% at λ = 840 nm (NIR-spectrum). The energy gap is reduced from 3.31 eV to 3.16 eV while the SnO2 concentration increases from 1.25gm/100 ml to 5gm/100 ml. The obtained results showed that SnO2 thin film are appropriate for numerous electronic, photocatalytic and photonics fields. The SnO2 thin film employed for self cleaning against organic dyes. The results indicate that the SnO2 NPs are very important to apply as a coating nanolayer for self cleaning to obtain on cleaning environment. [ABSTRACT FROM AUTHOR]

In this study, we present the first comprehensive investigation of the temperature-dependent band gap energy of anatase TiO2 nanoparticles, utilizing transmission measurements in the range of 10–300 K. X-ray diffraction pattern exhibited nine peaks related to tetragonal crystal structure. Scanning electron microscope image showed that the nanoparticles with the dimensions of 25–50 nm were found as micrometer sized agglomerated. When the spectrum obtained as a result of the transmission measurements was analyzed, it was seen that the band gap energy decreased from 3.29(5) to 3.26(6) eV as the temperature was increased from 10 to 300 K. Temperature-band gap dependence was analyzed using Varshni and O'Donnell-Chen optical models and optical parameters of the TiO2 nanoparticles like absolute zero band gap energy, rate of change of band gap with temperature and average phonon energy were reported. [ABSTRACT FROM AUTHOR]

In modern chemistry, great interest has been paid to introducing outstanding photocatalysts for degrading organic pollutants. Herein, a highly efficient binary AgI/Ag2WO4 photocatalyst was prepared from AgI and Ag2WO4 nanoparticles (NPs) and characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), UV–Vis diffuse reflectance spectroscopy (DRS), electrochemical impedance spectroscopy (EIS), and Fourier transform infrared (FT-IR) techniques. In the Scherrer model, the average crystallite sizes of 34.9, 42.0, and 24.1 nm were estimated for the AgI, Ag2WO4, and the binary catalyst, while the values were 91, 13, and 85 nm by the Williamson-Hall model. FTIR confirmed the presence of W–O–W, O–W–O, Ag-I, and O–Ag–O bonds in the coupled material. DRS results showed absorption edge wavelengths of 451, 462, and 495 nm (corresponding to the band gap values of 2.75, 2.68, and 2.51 eV) for Ag2WO4, AgI, and AgI/Ag2WO4 catalyst, respectively. Synergistic photocatalytic activity of the coupled system was achieved towards ceftriaxone (CTX) in an aqueous solution (about 33% 10 ppm CTX solution was degraded without any optimization in the initial conditions of catal dose 0.3 g/L (Ag2WO4:AgI with mole ratio 1:2 and 30 min abrasion time), and irrad. time 45 min, CCTX). This boosted effect depended on the AgI:Ag2WO4 mole ratio and grinding time for the mechanical preparation of the binary catalyst (optimums: mole ratio of 4:1 and time 30 min). The photodegradation kinetics obeyed the Hinshelwood model with the apparent first-order rate constant (k) of 0.013 min−1 (t1/2 = 53.30 min). Performing the COD on the photodegraded CTX solutions got a Hinshelwood plot with a slope of 0.019 min−1 (t1/2 = 36.5 min). [ABSTRACT FROM AUTHOR]

In this work, AlN nanoparticles were prepared by arc discharge method and transformer oil-based nanofluids containing different concentrations of these nanostructures were prepared and their thermal conductivities and stabilities were investigated at various temperatures. Two aluminum rods were used as the electrodes and nitrogen gas was used as the arc atmosphere. To investigate the factors that influence the size and purity of the nanoparticles, the nitrogen gas pressure and the current flowing through the electrodes were changed. Based on XRD measurements, it was observed that at the pressure of 2 atm. and current of 100 A, the highest purity phase was achieved. Scanning electron microscope (SEM) images indicated that the smallest samples were the ones that were made at a pressure of 3 atm. and arc current of 400 A and had an average particle size of about 67 nm. The band gap of nanoparticles was obtained at 5.6 eV using the Tauc method. Then, transformer oil-based nanofluids with concentrations of 0.5, 1, 2, and 4 wt.% of AlN were prepared and their thermal conductivities and stabilities were investigated. The nanofluid with 4 wt.% of AlN nanoparticles at 60 °C showed a maximum thermal conductivity enhancement of 9.4%. Nanofluids were completely stable for up to a week. [ABSTRACT FROM AUTHOR]

In the present study, binary (Cu9S5 and SnS2) and ternary (Cu2SnS3—CTS) have been prepared by a one-pot thermal decomposition of copper(II) bis (N-methyl-N-paramethoxyphenyl) dithiocarbamate, dimethyltin(IV) bis (N-methyl-N-paramethoxyphenyl) dithiocarbamate, and the co-thermal decomposition of both complexes in oleylamine, respectively. The crystallinity and structural properties of the semiconductor nanoparticles were investigated using X-ray diffraction analyses, which confirmed the purity of the Cu9S5, SnS2, and Cu2SnS3 nanoparticles. Morphological studies using scanning electron microscope (SEM) showed hexagonal plate-like particles of the SnS2, quasi-spherical shapes for both Cu9S5 and Cu2SnS3 in the SEM images. These morphologies were also corroborated by the transmission electron microscopic analysis. Optical analysis by absorption spectroscopy showed absorption in the visible to near infra-red region, and an estimated band gap energy that were greater than their respective bulk. The visible-light photocatalytic evaluation of these nanomaterials showed good activities for the photo-enhanced degradation of methyl orange (MO), with the SnS2 and Cu2SnS3 exhibiting comparable properties (> 90% removal efficiency) and better than the Cu9S5 nanoparticles with < 90% efficiency. The high activity of SnS2 and Cu2SnS3 could be attributed to morphology as well as their structural properties. The method of synthesis showed a facile approach to obtaining these binary and ternary nanomaterials by simple use of precursor compounds, which may also be extended to other metal sulphides. [ABSTRACT FROM AUTHOR]

The synthesis of undoped barium oxide (BaO) and neodymium (Nd)-doped BaO nanoparticles (NPs) was carried out through the co-precipitation technique. The synthesis of cubic structure BaO NPs was confirmed through X-ray diffraction (XRD). The crystallite sizes calculated from X-rays diffractometric (XRD) results for undoped BaO and Nd-doped BaO were 10.50 nm and 10.04 nm, respectively. The morphological study and percent composition of synthesized NPs were investigated using a scanning electron microscope and energy-dispersive X-ray analysis. Thermogravimetric analysis confirmed the decomposition of precursor to BaO after annealing at ~ 500 °C. The band gap energy calculated for undoped BaO was 3.7 eV. The substitution of Nd to BaO decreased this value to 3.4 eV. The activation energy calculated for the doped BaO and undoped BaO was 16.5 kJ/mol and 22.5 kJ/mol, respectively. The Nd-doped BaO degraded about 96.4% dye, while the undoped BaO NPs degraded about 86.6% dye within 120 min. The synthesized BaO NPs were used as novel catalysts for the photodegradation of malachite green (MG) dye by varying irradiation time, catalyst dose, pH, temperatures and dye initial concentration. The maximum degradation efficiency was achieved at pH 4, catalyst dose 10 mg, dye initial concentration 50 ppm, and at a temperature of 50 °C. The dye degradation was also studied using the recovered catalysts. [ABSTRACT FROM AUTHOR]

The present study report is on synthesis and characterization of cadmium oxide nanoparticles (CdO) which were prepared by the microwave irradiation method. The prepared nanoparticles were characterized by various techniques such as X-ray diffraction, Fourier transforms infrared spectroscopy, scanning electron microscope, energy dispersive spectroscopy, transmission electron microscope, ultraviolet visible diffuse reflectance spectroscopy, and photoluminescence techniques. The CdO nanoparticles are found to be cubic in structure from its XRD pattern. The average particle size was calculated from XRD analysis, which varies from 37 to 19 nm. The nail shaped morphology was confirmed by TEM analysis. Linear optical studies were used to determine the band gap energy of CdO nanoparticles. The DC electrical conductivity studies described the annealed CdO have a maximum conductivity compared to as prepared. The nail shaped CdO nanostructure was coated on the p-Si substrate using jet nebulizer spray pyrolysis technique. The fabricated Ag/n-CdO/p-Si diode parameters were evaluated in darkness and below different light sources such as Halogen and Metal halide lamps. [ABSTRACT FROM AUTHOR]