Papers by Keyword: Flame Spray Pyrolysis

Abstract: Flame Spray Pyrolysis is an attractive technology for the synthesis of nanosized materials with distinct characteristics. Industry leaders such as Cabot, Cristal, DuPont, Evonik, and Ishihara manufacture flame-made materials in millions of tons per year including carbon blacks. Herein we exemplify the application of large-scale FSP process for the synthesis of highly active photocatalysts, able to achieve high H₂, O2 production yields from H₂O. Precise control of W-doping along with controlled Scheelite-phase BiVO₄ is a benchmark oxygen-evolving nanocatalyst. Double-Nozzle FSP is demonstrated to allow the production of highly efficient {noble metal} TiO₂ heterostructures. Key-Performance-Indicators that allow transition of Lab-Scale to Industrial-Scale engineering of semiconductors are discussed, including cost-analysis and environmental impact of the production process.

Abstract: In the present work, vanadium pentoxide (V₂O₅) nanoparticles have been investigated for monitoring ethanol (C₂H₅OH) at ppm levels in air. A one-step flame spray pyrolysis (FSP) process has been applied for the synthesis of vanadium pentoxide (V₂O₅) and platinum-loaded vanadium pentoxide (Pt-V₂O₅) nanoparticles. The samples have been studied to characterize their morphological and microstructural properties by X-ray diffraction and transmission electron microscopy. Pt addition to V₂O₅ samples were verified by energy dispersive X-ray spectrometry mode. The specific surface area of the nanoparticles was measured by nitrogen adsorption method. The application of the produced nanoparticles as sensitive and selective ethanol resistive sensor has been demonstrated. The Pt-loaded V₂O₅ sensor has shown higher response towards ethanol at ppm-level concentrations compared to unloaded one.

Abstract: This paper presented a novel synthesis method for yttria-stabilized zirconia (YSZ) by using the flame spray pyrolysis (FSP) method. Spherical and dense YSZ particles for thermal barrier coating were successfully synthesized by FSP from the nebulized precursor solution. XRD results revealed that the YSZ powder is only composed of tetragonal phase particles. Most particles are a few hundred nanometers in diameter and their sizes are mainly dependent on the concentration of the precursor solution, while flame condition has little effect. Particle size and morphology are greatly affected by the precursor composition. Particles synthesized from ethanol precursor solution are more uniform and better-defined than those from aqueous solution.

Abstract: Undoped ZnO and 0.5−5.0 at.% Sn-doped ZnO nanoparticles were synthesized by flame spray pyrolysis (FSP) using zinc naphthenate and tin (II) 2-ethylhexanoate dissolved in xylene as the precursors under a 5/5 (precursor/oxygen) flame condition. UV-Vis absorption characteristics of the samples were investigated for understanding and relating with the physiochemical characteristics in photocatalytic applications. Kinetic analyzes indicated that the photodegradation rates of phenol could be approximated as pseudo-first-order and zero-order kinetics in the case of undoped ZnO and Sn-doped ZnO nanoparticles respectively, according to the Langmuir-Hinshelwood model. The effect of Sn doping revealed the deterioration of the phenol photodegradation performance over ZnO-based catalysts, possibly due to the formation of a deep state in the ZnO band gap energy.

Abstract: ZnO nanoparticles doped with 0.2-2 at.%Pt were successfully produced in a single step by flame spray pyrolysis (FSP) technique using zinc naphthenate and platinum (II) acetylacetonate dissolved in xylene. The particle properties were analyzed by XRD, BET and TEM. Depending on FSP conditions, ZnO nanoparticles and nanorods were observed. The crystallite sizes of ZnO spheroidal particles were found to be ranging from 5 to 20 nm, while ZnO nanorods were seen to be 5-20 nm in width and 20-40 nm in length. ZnO sensing films were prepared using Al2O3 substrate interdigitated with Au electrodes by spin-coating technique. The gas sensing properties toward carbon monoxide (CO) was studied at the operating temperatures ranging from 200 to 350°C. It was found that the 0.2 at.%Pt/ZnO sensing film showed the highest sensitivity and the fastest response time at 350°C.

Abstract: Flame Spray Pyrolysis (FSP) was performed for the synthesis of high specific surface area (SSABET) of SnO2 nanopowders (141.6 m2/g) and supported palladium (Pd) nanoparticles containing 0.2-3 wt%Pd with controlled size and a crystallinity in a single step. The particles properties were further characterized by XRD, BET and TEM analyses. The crystalline particles were used for sensing film preparation by spin coating. It was found that the flame-spray-made 0.2 wt%Pd/SnO2 sensor showed higher and faster response to reducing H2 gas than pure flame-spray-made SnO2 sensor.