Nano-sized Tin Oxide Powders Research Articles

Preparation of Nano-Sized Tin Oxide Powder from Waste Pb-Free Solder by Direct Nitric Acid Leaching

Nano-sized tin oxide particles were prepared by nitric acid (HNO3leaching of Pb-free solder containing tin (Sn), silver (Ag), and copper (Cu) as main components. During the nitric acid leaching, Ag and Cu were dissolved whereas Sn was not detected in the leach solution and the leaching efficiencies of Ag and Cu increased with increasing temperature and HNO3 concentration. The precipitates were analyzed with X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM). The tin precipitate was determined to be tin oxide by XRD and nano-sized particles were observed in the SEM and TEM images. The larger particle size was observed in the leaching condition of slow leaching rate. The purity and particle size of tin precipitate, obtained from the leaching test performed in the 2 mol/L HNO3 solution at 90 C and 400 rpm, were 99.986% and 6.03 nm, respectively.

Infleunce of Nozzle Tip Size on the Preparation of Nano-Sized Tin Oxide Powder by Spray Pyrolysis Process

In this study, using a tin chloride solution as the raw material, a nano-sized tin oxide powder with an average particle size below 50 nm is generated by a spray pyrolysis process. The properties of the tin oxide powder according to the nozzle tip size are examined. Along with an increase in the nozzle tip size from 1 mm to 5 mm, the generated particles that appear in the shape of droplets maintain an average particle size of 30 nm. When the nozzle tip size increases from 1 mm to 2 mm, the average size of the generated particles is around 80-100 nm, and the ratio of the independent particles with a compact surface structure increases significantly. When the nozzle tip size is at 3 mm, the majority of the generated particles maintain the droplet shape, the average size of the droplet-shaped particles increases remarkably compared to the cases of other nozzle tip sizes, and the particle size distribution also becomes extremely irregular. When the nozzle tip size is at 5 mm, the ratio of droplet-shaped particles decreases significantly and most of the generated particles are independent ones with incompact surface structures. Along with an increase in the nozzle tip size from 1 mm to 3 mm, the XRD peak intensity increases, whereas the specific surface area decreases greatly. When the nozzle tip size increases up to 5 mm, the XRD peak intensity decreases significantly, while the specific surface area increases remarkably.

Effect of processing on the particle size of tin oxide nano-powders

Nano sized tin oxide powders have been syn- thesized via two different chemical routes namely solid- state and sol-gel route for the fabrication of tin oxide gas/ odors sensor. The synthesized powders have been charac- terized by simultaneous thermo gravimetric and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), field emission scanning electron microscopy (FE- SEM) and Fourier transform infrared (FTIR) spectroscopy. The effect of synthesis routes have been investigated on particle size and morphology of tin oxide powders. Powder XRD patterns show that the synthesized powders have tetragonal (rutile) crystal structure. FESEM of formed thick films reveal that powder prepared by solid-state reaction route is less agglomerated as compared to the powder prepared by sol-gel route. XRD and FESEM indicate that there is the formation of tin oxide nanoparticles in the range of 15-50 nm. FTIR spectrums of synthesized pow- ders show Sn-O or Sn-O-Sn stretching modes and its lattice modes at 615 and 494 cm -1 .

Effects of Air Pressure on the Fabrication of Nano-Sized Tin Oxide Powder by Spray Pyrolysis Process

In this study, nano-sized tin oxide powder with an average particle size of below 50 nm is prepared by the spray pyrolysis process. The influence of air pressure on the properties of the generated powder is examined. Along with the rise of air pressure from <TEX>$0.1kg/cm^2$</TEX> to <TEX>$3kg/cm^2$</TEX>, the average size of the droplet-shaped particles decreases, while the particle size distribution becomes more regular. When the air pressure increases from <TEX>$0.1kg/cm^2$</TEX> to <TEX>$1kg/cm^2$</TEX>, the average size of the dropletshaped particles, which is around 30-50 nm, shows hardly any change. When the air pressure increases up to <TEX>$3kg/cm^2$</TEX>, the average size of the droplet-shaped particles decreases to 30 nm. For the independent generated particles, when the air pressure is at <TEX>$0.1kg/cm^2$</TEX>, the average particle size is approximately 100 nm; when the air pressure increases up to <TEX>$0.5kg/m^2$</TEX>, the average particle size becomes more than 100 nm, and the surface structure becomes more compact; when the air pressure increases up to <TEX>$1kg/cm^2$</TEX>, the surface structure is almost the same as in the case of <TEX>$0.5kg/cm^2$</TEX>, and the average particle size is around 80- 100 nm; when the air pressure increases up to <TEX>$3kg/cm^2$</TEX>, the surface structure becomes incompact compared to the cases of other air pressures, and the average particle size is around 80-100 nm. Along with the rise of air pressure from <TEX>$0.1kg/cm^2$</TEX> to <TEX>$0.5kg/cm^2$</TEX>, the XRD peak intensity slightly decreases, and the specific surface area increases. When the air pressure increases up to <TEX>$1kg/cm^2$</TEX> and <TEX>$3kg/cm^2$</TEX>, the XRD peak intensity increases, while the specific surface area also increases.

Preparation of Nano-Sized Tin Oxide Powder from Tin Chloride Solution by Spray Pyrolysis Process

In this study, by using tin chloride solution as a raw material, a nano-sized tin oxide powder with an average particle size below 50 nm is generated by a spray pyrolysis process. The properties of the generated tin oxide powder depending on the inflow speed of the raw material solution are examined. When the inflow speed of the raw material solution is 2 ml/min, the majority of generated particles appear in the shape of independent polygons with average size above 80-100 nm, while droplet-shaped particles show an average size of approximately 30 nm. When the inflow speed is increased to 5 ml/min, the ratio of independent particles decreases, and the average particle size is approximately 80-100 nm. When the inflow speed is increased to 20 ml/min, the ratio of droplet-shaped particles increases, whereas the ratio of independent particles with average size of 80-100 nm decreases. When the inflow speed is increased to 100 ml/min, the average size of the generated particles is around 30-40 nm, and most of them maintain a droplet shape. With a rise of inflow speed from 2 ml/min to 5 ml/min, a slight increase of the XRD peak intensity and a minor decrease of specific surface area are observed. When the inflow speed is increased to 20 ml/min, the XRD peak intensity falls dramatically, although a significant rise of specific surface area is observed. When the inflow speed is increased to 100 ml/min, the XRD peak intensity further decreases, while the specific surface area increases.

Influences of reaction factors on the nano-sized tin oxide powder by spray pyrolysis process

In this study, by using tin chloride solution as the raw material, a nano-sized tin oxide powder with an average particle size below 50 nm is generated by spray pyrolysis reaction. This study also examines the influences of the reaction temperature and the concentration of raw material solution on the powder properties. As the reaction temperature increases from 800 to 850°C, the average particle size of the generated powder increases from 20 nm to 30 nm, the intensity of XRD peak increases, and the specific surface area decreases. As the reaction temperature reaches 900°C, produced powder of droplet type are composed of nano-sized particles with an average size of 30 nm, while the average particle size of the independent type increases remarkably up to 80-100 nm, and the particle surface becomes more compact. As the reaction temperature reaches 950°C, most of the particles appear mutually independent, while the average particle size is around 70 nm. When the tin concentration reaches 75 g/L, the average particle size of the generated powder is below 20 nm. When the tin concentration reaches 150 g/L, the powder of droplet type are composed of nano particles with an average size around 30 nm, whereas the average size of the independent particles increases up to 80-100 nm. Also, the intensity of XRD peak increases, and the specific surface area decreases. When the concentration reaches 400 g/L, the droplet types are composed of nano-particles with an average size of 30 nm. Also, the intensity of XRD peak increases, and the specific surface area decreases.

Fabrication of Nano-Sized Tin Oxide Powder by Spray Pyrolysis Process

AbstractBy using tin chloride solution as the raw material, a nano-sized tin oxide powder with average particle size below 50 nm is generated by spray pyrolysis reaction. This study also examines the influences of the reaction parameters such as reaction temperature and the concentration of raw material solution on the powder properties. As the reaction temperature increases from 800 to 850 ℃, the average particle size of the generated powder increases from 20 nm to 30 nm. As the reaction temperature reaches 900 ℃, the droplets are composed of nano-particles with average size of 30 nm, while the average size of individual particles increases remarkably up to 80˜100 nm. When the tin concentration reaches 75 g/L, the average particle size of the powder is below 20 nm. When the tin concentration reaches 150 g/L, the droplets are composed of nano particles with average size around 30 nm, whereas the average size of independent particles increases up to 80˜100 nm. When the concentration reaches 400 g/L, the droplets are composed of nano-particles with average size of 30 nm.

Synthesis of nano-sized tin oxide powder by argon plasma jet at atmospheric pressure

Nano-sized SnO2 particles were prepared with an argon plasma jet using SnCl4 and O2 as raw materials. SnCl4, which was easily vaporized at room temperature, and O2 were injected into the reactor through the reaction tube in the vapor phase by an Ar-carrier gas. The product of the reaction with the argon plasma jet was synthesized by rapid quenching. Most of the prepared powders were collected on an inside wall of the reactor. Because this process does not need any other after-treatment, SnO2 powder could conveniently be synthesized. As a process parameter, the flow rate of oxygen gas was kept below the constant flow rate of the carrier gas and additional nitrogen gases. The characteristics of the powders were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). TEM and SEM analysis found the particle sizes of SnO2 to be from 3 nm to 20 nm, and images of the particles were also produced. The cross stripes on SnO2 powder also have been studied. The effects of O2 parameters were investigated to optimize synthesis of tin oxide with XRD analysis. An increase in O2 concentration does not ensure good results; therefore it was possible to find optimum conditions for synthesis of SnO2 particles.

Gas sensing properties of nanocrystalline SnO 2 prepared in solvent media using a microwave assisted technique

Nanosized tin oxide powders were obtained by microwave procedure for their application on gas sensors. Microwave treatment with a wavelength of 2.45 GHz produces nanocrystalline powder whose sensing properties are determined by the solvent used during the synthesis process. The gas sensitivity measurements showed that the new aqueous route is better in terms of sensitivity as well as response/recovery time. The microwave assisted heating was found to be a convenient and efficient means of sol gelation and was found to improve the gas sensitivity of the powder as compared to the powder prepared in organic medium.

Study of structural and microstructural properties of SnO 2 powder for LPG and CNG gas sensors

Nanosized tin oxide powders were obtained using microwave assisted synthesis procedure for their application on gas sensor technology. XRD results showed the presence of casseterite structure. As found from the XRD line broadening the crystallite size of the powders were in the range of 20–14 nm even after heating to 600 °C for 3 h. TEM results showed microwave assisted powders to be less agglomerated as compared to conventional process. Enhancement in LPG and CNG gas sensitivity was realized after microwave irradiation to a hydrosol solution.

Properties of nanocrystalline SnO 2 obtained by means of a microwave process

Nanosized tin oxide powders were obtained for application in gas sensor technology, using an innovative technique, based on a Microwave treatment with a wavelength of 2.45 GHz, which produces pure and in situ noble metal catalysed powder precursors in just a few minutes. Further stabilisation treatments—conventional heating, OH-stimulated microwaves and combined treatments—were also considered. Material structural characterisation of Pt and Pd in situ catalysed, and pure SnO 2 is presented, showing the suitability of this procedure for gas sensor applications.

CO–CH 4 selectivity enhancement by in situ Pd-catalysed microwave SnO 2 nanoparticles for gas detectors using active filter

Nanosized tin oxide powders were obtained using microwave procedure for their application on gas sensor technology. This technology allows taking advantage of low cost and high volume mass production for the easy in situ introduction of the palladium catalytic additive. The effects of a controlled high palladium catalysation, reaching active filter properties, are reported showing an enhancement of the selectivity for CO and CH 4. In this work, electrical results of the sensor performances are discussed and correlated with their structural parameters and the used technological procedures. Especial emphasis has been devoted to the active filter efficiency deduced from CO consumption measurements. The applicability to the present state of the art in sensor technology of such active-filter catalysed SnO 2 is shown by means of its implementation in micromachined substrates operated in pulsed mode.

Microwave processing for the low cost, mass production of undoped and in situ catalytic doped nanosized SnO 2 gas sensor powders

Nanosized tin oxide powders were obtained for application in thick film gas sensor technology. This requires an innovative technique, involving the use of microwave energy with a wavelength of 2.45 GHz, which produces doped or undoped powder precursors in just a few minutes. Further stabilisation treatments — conventional heating, OH-stimulated microwaves and combined treatments — were also considered. Reproducibility, low cost and suitability for mass production demonstrate the industrial and scientific feasibility of this new procedure. Material structural characterisation and electrical properties after gas exposure of improved sensors of Pt and Pd in situ doped, and undoped SnO 2 are introduced, showing the suitability of the material.