Characterization and photocatalytic activity of Pd-doped ZnO nanoparticles synthesized by flame spray pyrolysis

TiO2/perlite composites were prepared via facile one-step flame spray pyrolysis (FSP) route. Titanium alkoxide (TIPO) and expanded perlite were used as Ti source and substrate, respectively. Precursor TIPO-ethanol solutions containing homogeneously dispersed perlite particles were processed through FSP setup at different experimental conditions regarding the gas flow and precursor supply rates. The structure, morphology, and the composition of the obtained powders were investigated. The porosity and the light absorbance of the TiO2/perlite composites were examined and their photocatalytic activity in NO oxidation was evaluated. Commercial titania powder P25 was also FSP processed and investigated for comparison. The XRD analysis revealed that biphased titania with different anatase-rutile ratio and particles size 20–40 nm was synthesized onto the perlite which according to microscopy results was covered by neck-connected TiO2nanoparticles. The anatase-rutile interplay was also demonstrated by the Raman spectra where presence of Si-O-Ti vibrational modes was observed for some samples. The UV-Vis diffuse reflectance spectra of the TiO2/perlite composites revealed up to 70% reflection that was connected to the presence of the gray perlite and superficial carbon. The best photocatalytic activity of the composites was connected to almost equal anatase-rutile ratio and possible synergetic effect of the two TiO2phases.

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Hydrogen and Ethanol Sensing Properties of Pd-Loaded ZnO Nanoparticles Synthesized by Flame Spray Pyrolysis

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1131.146 ◽

2015 ◽

Vol 1131 ◽

pp. 146-152 ◽

Cited By ~ 2

Author(s):

Chawarat Siriwong ◽

Jintaporn Yimchoy ◽

Sangtian Nabsanit ◽

Anurat Wisitsoraat ◽

Sukon Phanichphant

Keyword(s):

Electron Microscopy ◽

Spray Pyrolysis ◽

Zno Nanoparticles ◽

Gas Sensing ◽

Flame Spray Pyrolysis ◽

Flame Spray ◽

Coating Film ◽

Sensing Applications ◽

Transmission Electron ◽

Ethanol Sensing

Pure ZnO and Palladium (Pd)-loaded ZnO nanoparticles containing 0.25, 0.50, 0.75 and 1.0 mol% of Pd were successfully synthesized by flame spray pyrolysis (FSP) and characterized for hydrogen and ethanol sensing applications. The crystalline phase, morphology and size of these nanoparticles were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM) in order to correlate physical properties with gas sensing performance. The sensing films were fabricated by coating nanoparticles with organic paste composed of terpineol and ethyl cellulose as a vehicle binder on Al2O3 substrate interdigitated with gold electrodes. The film thicknesses were varied by controlling the numbers of coating. Film morphologies of gas sensors were characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Moreover, response time and sensitivity of these sensors towards hydrogen and ethanol were evaluated under operating temperatures ranging from 200 ̶ 350°C in dry air. Finally, The optimum amount of loading Pd and film thickness were investigated.

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