Tin Dioxide Nanoparticles Research Articles

The effect of Sn content on the electrocatalytic properties of Pt–Sn nanoparticles dispersed on graphene nanosheets for the methanol oxidation reaction

Direct methanol fuel cell (DMFC) electrode catalysts with improved electrochemical properties have been prepared by dispersing platinum–tin (Pt–Sn) nanoparticles onto graphene sheets. During the deposition, a majority of the oxygenated functional groups on the graphene oxide nanosheets were removed, resulting in the formation of graphene. Microstructural characterization shows that metallic Pt, Pt–Sn alloy and tin dioxide (SnO2) nanoparticles were distributed on the graphene sheets, representing different lattice planes during the synthetic process. In terms of the electrocatalytic properties, graphene-supported Pt–Sn and graphene-supported Pt catalysts exhibited much higher current densities compared with that of commercial carbon black-supported Pt catalysts. Graphene-supported Pt–Sn increased the electrocatalytic activity, which is strongly influenced by the addition of Sn in its alloyed and oxidized forms, boosting the reaction more readily because of the lower oxidation potential.

Recovering Nano-Sized SnO<sub>2</sub> from Electronic Wastes by Ultrasonic-Assisted Electrochemical Method

Tin dioxide nanoparticles were directly one-step recovered from electronic wastes using ultrasonic-assisted electrochemical method. The products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), which indicated that the average size of tetragonal SnO2 is 100 nm. The experiment parameters, such as the concentration of electrolyte, electrolysis current, reaction time and electrode distance, were also discussed. The proposed method is high energy efficient, non-toxic and environment-friendly, and suitable for the recovering of electronic wastes under the controllable reaction condition at room temperature.

UV-assisted alcohol sensing using SnO2 functionalized GaN nanowire devices

Abstract A chemiresistor type sensor for selective alcohol sensing has been realized from gallium nitride (GaN) nanowires (NWs) functionalized with sputter-deposited tin dioxide (SnO2) nanoparticles. Two-terminal devices were fabricated using standard microfabrication techniques with the individual NWs air-bridged between the two metal contact pads. Through a combination of X-ray diffraction (XRD), electron-backscatter-diffraction (EBSD), and TEM/STEM techniques, we confirmed the presence of rutile SnO2 nanocrystals on the GaN surface. A change in device current is observed when the device is exposed to alcohol vapors (methanol, ethanol, propanol, and butanol) at room temperature under 215–400 nm UV illumination with 3.75 mW/m2 intensity at 365 nm wavelength. The sensor reproducibly responded to a wide range of alcohol vapor concentrations, from 5000 μmol/mol (ppm) down to 1 μmol/mol (ppm) in air. Notably, the devices show low sensitivity to acetone and hexane, which allows them to selectively detect the primary alcohol vapors mixed with these two common volatile organic compounds (VOCs). The sensor response was not observed without UV excitation. From the experimental results we found a relationship between the response towards the alcohol vapors and the length of carbon chain in the molecule: the chemiresistive response decreases with the increasing carbon chain from methanol to n-butanol. In addition, we observed that the isomeric branching in i-propanol and i-butanol caused reduced response as compared to n-propanol and n-butanol, respectively. We have qualitatively explained the sensor operation by employing a mechanism, which includes oxidation of analyte molecules on the SnO2 surface, leading to enhanced photoconductivity in GaN nanowire.

Controlled Synthesis and Enhanced Catalytic and Gas‐Sensing Properties of Tin Dioxide Nanoparticles with Exposed High‐Energy Facets

A morphology evolution of SnO(2) nanoparticles from low-energy facets (i.e., {101} and {110}) to high-energy facets (i.e., {111}) was achieved in a basic environment. In the proposed synthetic method, octahedral SnO(2) nanoparticles enclosed by high-energy {111} facets were successfully synthesized for the first time, and tetramethylammonium hydroxide was found to be crucial for the control of exposed facets. Furthermore, our experiments demonstrated that the SnO(2) nanoparticles with exposed high-energy facets, such as {221} or {111}, exhibited enhanced catalytic activity for the oxidation of CO and enhanced gas-sensing properties due to their high chemical activity, which results from unsaturated coordination of surface atoms, superior to that of low-energy facets. These results effectively demonstrate the significance of research into improving the physical and chemical properties of materials by tailoring exposed facets of nanomaterials.

Novel Ag decorated biomorphic SnO2 inspired by natural 3D nanostructures as SERS substrates

In this work, we demonstrated a novel surface-enhanced Raman scattering (SERS) substrate inspired by natural nanostructures of butterfly wing scales. By facile and low-cost procedures, we synthesized the substrate composed of tin dioxide (SnO2) and silver (Ag) nanoparticles (NPs). Micrographs and composition analyses exhibited the morphologies of Ag-Biomorphic SnO2 which inherited the natural three-dimension (3D) periodic nanostructures, and characterized the elemental information of the nanocomposites. SERS spectra were measured by using rhodamine 6G (R6G) as analyte molecules. The satisfying sensibility (with the enhancement factor about 106) and good reproducibility of this SERS-active substrate revealed the effectiveness of our work. It is expected that this substrate would be a potential candidate for relative applications.

Interaction of N-(2-Methyl Thio Phenyl)-2-Hydroxy-1-Naphthaldimine with Tin Dioxide Nanoparticles: A Spectroscopic Approach

The interaction of N-(2-methyl thiophenyl)-2-hydroxy-1-naphthaldimine (NMTHN) with tin dioxide nanoparticles (SnO2 NPs) has been investigated by spectroscopic tools such as absorption and fluorescence spectroscopy. Absorption spectroscopy reveals the formation of ground state complex. Fluorescence spectroscopy has been used to study the signatures of fluorescence quenching. SnO2 NPs are found to quench the intrinsic fluorescence of NMTHN via static and dynamic quenching. The deviation from linearity in the Stern-Volmer plot has been observed.

Effects of particle size on the structural and hyperfine properties of tin dioxide nanoparticles

In this work, we report on the study of SnO2 nanoparticles prepared by a polymer precursor method. X-ray diffraction (XRD) data analysis evidenced the formation of only the tetragonal rutile-type phase for the as-grown and thermally annealed samples. A mean grain size of about 11 nm for the as-prepared sample has been determined. This mean size increases after the thermal annealing and with the annealing temperature. The room temperature Mossbauer spectra (MS) were well fitted using a quadrupole splitting (QS) distribution. The isomer shift (IS) tends to increase when the grain size decreases. That increase has been associated to the extra s-electron density generated by the oxygen vacancies.

Synthesis and Gas Sensitivity of SnO<sub>2</sub> Nanoparticles

Tin dioxide (SnO2) nanoparticles have been synthesized in bulk quantity by thermal evaporation of SnO powder. The x-ray powder diffraction (XRD) analysis indicates that the nanoparticles are the tetragonal rutile structure of SnO2. Scanning electron microscopy (SEM) analysis shows that the size of the synthesized SnO2 nanoparticles is relatively homogeneous with diameter of about 10 nm. Gas-sensing components have been manufactured with the SiO2 nanoparticles. Their performances indicate that it has high sensitivity and selectivity to LPG, and the max sensitivity appears at 280°C, compared with C2H5OH, H2, CO and CH4.

Synthesis of Tin Dioxide Nanoparticles and Nanorods by Hydrothermal Method and Gas Sensing Characteristics

Tin dioxide nanoparticles and nanorods were successfully prepared by hydrothermal method using tin chloride, liquid ammonia, sodium hydroxide and cetyltrimethyl ammonium bromide (CTAB) as starting materials. The crystalline and structure features of the tin dioxide nanomaterial were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray analysis. Sensor devices were fabricated by coating SnO2 nanomaterials on the front side of silicon substrates attached with Pt-interdigited electrodes before annealed at 600°C for 30 minutes. Also, the films were measured to LPG and alcohol vapor at operating temperature in the range of 220-330°C. In addition, the sensitivity and selectivity of sensor were discussed. [DOI: 10.1380/ejssnt.2011.503]

One-Step Synthesis of Carbon-Coated Tin Dioxide Nanoparticles for High Lithium Storage

Carbon-coated SnO2 nanoparticles were synthesized by a simple one-pot hydrothermal treatment. During the hydrothermal process, SnO2 was formed by the hydrolysis of tin(II) dichloride dihydrate (SnCl2·2H2O) in alkali solution, while sucrose was used as the carbon source to form the coated polysaccharide shell on the SnO2 nanoparticles. In the obtained carbon-coated SnO2 nanoparticles, SnO2 nanocrystals with a diameter of 4 nm were observed to be homogeneously dispersed in the particles. After calcination, the product exhibited improved lithium storage properties, as compared to pure SnO2 nanoparticles. The carbon-coated SnO2 nanoparticles exhibit 430 mAh g−1 reversible capacities after 100 cycles and an average capacity fading of 0.2% per cycle after the 20th cycle. The good electrochemical performances of the carbon-coated SnO2 nanoparticles indicate that the obtained carbon shell can effectively increase the stability of the active materials and improve the cycling performance of oxide-based anode materials for lithium-ion batteries.

A SnO2 Nanoparticle/Nanobelt and Si Heterojunction Light-Emitting Diode

Single-crystalline zero-dimensional tin dioxide (SnO2) nanoparticles and one-dimensional SnO2 nanobelts were synthesized on silicon (Si) substrates with different seed layer coatings by simple vapo...

Multifunctional Nanocomposite Thin Films by Aerosol‐Assisted CVD

AbstractThe aerosol‐assisted (AA)CVD reaction of titanium isopropoxide and a solution of preformed tin dioxide nanoparticles leads to the production of titanium dioxide/tin dioxide nanocomposite thin films on glass substrates. Scanning electron microscopy (SEM) studies show that film composition and morphology are linked, with larger island sizes being observed as more tin dioxide nanoparticles are incorporated into the films. Reflectance measurements performed on the nanocomposite thin films show an increase in reflection in the infrared (IR) portion of the spectrum with increased tin dioxide nanoparticle incorporation. Photocatalysis experiments indicate that the nanocomposite films are photo‐active with irradiation by 365 nm light. The nanocomposite thin films display both low‐emissivity and self‐cleaning functionalities; and as such they are multifunctional.

A novel chelating acid-assisted thermolysis procedure for preparation of tin oxide nanoparticles

Pure tin dioxide (SnO 2) nanoparticles were synthesized via thermolysis of tin phthalate and tin oxalate in the presence of oleic acid (OA) as solvent. Oleic acid (OA) was employed as an organic solvent, which can be applied to control particle growth and to stabilize the particles. The products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL) spectroscopy. The orthorhombic phase SnO 2 nanoparticles with average size about 12 nm were synthesized through thermolysis of tin phthalate in the presence of oleic acid.

A Low-Energy Room-Temperature Hydrogen Nanosensor: Utilizing the Schottky Barriers at the Electrode/Sensing-Material Interfaces

The hydrogen-sensing performance of a nanosensor integrating interdigitated electrodes with a gap of 100 nm and indium-oxide-doped tin dioxide nanoparticles is investigated at room temperature. The nonlinear behavior observed from the I/V curves of the sensor in air atmosphere indicated the presence of a Schottky barrier contact at the electrode/sensing-material interface. The linear I/V response obtained in hydrogen atmosphere suggested that the Schottky barrier height could be modulated in the presence of hydrogen. At a low applied voltage of 0.4 V and 0.09-vol% hydrogen gas exposure, a very large sensitivity of 2300 and a short response time of 127 s were recorded.

Preparation and characterization of SnO 2 nanoparticles using high power pulsed laser

Tin dioxide (SnO 2) nanoparticles having 3 nm size were synthesized by irradiating pure tin metal using high power Nd:YAG laser in deionized water. Formation of nano-SnO 2 crystallites was confirmed by X-ray diffraction (XRD) and AFM study. UV–vis absorption spectral studies showed a peak at 240 nm. FTIR spectrum showed a band in the range of 400–700 cm −1 which was assigned to Sn–O antisymmetric vibrations. Photoluminescence spectrum of synthesized SnO 2 nanoparticles showed peak corresponding to 3.175, 2.901 and 2.613 eV respectively.

Synthesis and characterization of SnO 2 nanoparticles embedded in silica by ion implantation

Tin dioxide nanoparticles embedded in silica matrix were fabricated by ion implantation combined with thermal oxidation. Silica substrate was implanted with a 150 keV Sn + ions beam with a fluence of 1.0 × 10 17 ions/cm 2. The sample was annealed for 1 h in a conventional furnace at a temperature of 800 °C under flowing O 2 gas. According to the structural characterization performed by X-ray diffraction and transmission electron microscopy techniques, metallic tetragonal tin nanoparticles with a volume average size of 12.8 nm were formed in the as-implanted sample. The annealing in oxidizing atmosphere promotes the total oxidation of the tin nanoparticles into tin dioxide nanoparticles with a preferential migration toward the surface of the matrix, where large and coalesced nanoparticles were observed, and a small diffusion toward the bulk, where smaller nanoparticles were found.

Gas-sensor properties of composite semiconductor films of substituted perylene and tin dioxide nanoparticles

Electrical conductivity of film samples of a composite constituted by a perylene derivative (3,4,9,10-perylenetetracarboxylic-dianhydride) and SnO2 nanoparticles was studied in adsorption of vapors of ammonia, toluene, aqueous hydrogen peroxide, ethanol, and water. A model of formation of the composite sample under study and a mechanism by which adsorbed molecules affect its electrical conductivity are suggested.

Synthesis, physicochemical characterization, and preliminary molecular modeling studies of SnO2 nanoparticles

AbstractThe aim of this work is to provide reliable and accurate experimental and modeling studies for the design and investigation of tin dioxide nanoparticles. SnO2 particles were prepared by following a sol–gel preparative route using tin (IV) alkoxide as the starting compound. The xerogels were thermally treated at 300, 500 and 700 °C, in different gaseous environments (oxygen, air, He). The powders were characterized for phase composition‐crystallinity, specific surface area and surface composition. Computational models of SnO2 were implemented, total energy of the systems was minimized by using COMPASS force field and further lattice parameters were assessed. The conditions adopted in the preparative route played an important role on the physicochemical properties of SnO2 nanoparticles. The size of the crystallites was found to increase with the heating temperature and to depend on the gassing atmosphere adopted during the thermal treatment. Computational and experimental lattice parameters are not appreciably affected by the variables of the synthesis and are in good agreement with structural data for the cassiterite lattice. Overall, the agreement between experimental data and simulation results is satisfactory. Copyright © 2010 John Wiley & Sons, Ltd.

Sensing characterization to NH 3 of nanocrystalline Sb-doped SnO 2 synthesized by a nonaqueous sol–gel route

Antimony-doped tin dioxide (ATO) nanoparticles with high crystallinity during solvothermal synthesis in alcohol were generated from the inorganic precursors (SnCl 4 and Sb(OC 2H 5) 3) and the cationic surfactant (cetyltrimethylammonium bromide, CTAB). The structural and morphological characterizations of the products were performed by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), N 2-sorption isotherm and X-ray photoelectron spectrum (XPS). The resulting particles were highly crystalline oxide particles in the nanometer range (10–14 nm). The indirect-heating sensors using ATO nanoparticles as sensitive materials were fabricated on an alumina tube with Au electrodes and platinum wires. The sensing properties of these sensors based on ATO nanoparticles were investigated. Compared to the original undoped sensor, the results show that the ATO nanoparticles have about 2.5 times increase in response and good dynamic response to NH 3 at low operating temperature (79 °C).

Fabrication of the hollow SnO 2 nanoparticles contained spheres as extreme ultraviolet (EUV) target

Extreme ultraviolet lithography (EUVL) is a promising technology for the volume production of the future integrated circuit. In this paper, hollow multilayer microcapsules which contained tin dioxide nanoparticles were fabricated successfully with layer-by-layer (LBL) technique. Compared with the previous reported results, the obtained capsules have rougher surface structure (60 nm in rms which measured by atomic force microscopy (AFM)) and lost their round shape even in solution because of the existing of the tin dioxide (SnO 2) nanoparticles. In order to lighten the mass of the target, heating treatment was introduced. After heating treatment, capsules’ sizes shrank about 28% (the average diameter changed from 4.9 μm to 1.4 μm). The narrowest bandwidth at 13.5 nm emission in EUV region was observed when the capsules were irradiated with CO 2 laser with an intensity of 2.9 × 10 10 W/cm 2, it is a little weaker than the previous result because of the mass difference of the target.