Nanocasting Synthesis of Ultrafine WO3 Nanoparticles for Gas Sensing Applications

Ultrafine WO3 nanoparticles were synthesized by nanocasting route, using mesoporous SiO2 as a template. BET measurements showed a specific surface area of 700 m 2/gr for synthesized SiO2, while after impregnation and template removal, this area was reduced to 43 m 2/gr for WO3 nanoparticles. HRTEM results showed single crystalline nanoparticles with average particle size of about 5 nm possessing a monoclinic structure, which is the favorite crystal structure for gas sensing applications. Gas sensor was fabricated by deposition of WO3 nanoparticles between electrodes via low frequency AC electrophoretic deposition. Gas sensing measurements showed that this material has a high sensitivity to very low concentrations of NO2 at 250°C and 300°C

Electrophoretic Deposition of Hydroxyapatite: Electrophoretic deposition of hydroxyapatite

The purpose of this study was to investigate the deposition of the hydroxyapatite(HA) coating via the electrophoresis procedure. The HAdeposition was performedin an ethanol, methanol, acetone and isopropanol suspension. Methanol was foundto be the best deposition media. Among the different environmental conditions,including the encapsulation of the samples under two vacuum types of pressure(10-5-10-4and 2×10-2Torr) and also thepurge of the argon gas in the tube-likefurnace, the optimum environment was the one demonstrating the encapsulation underthe vacuum pressure of 2×10-2Torr (washing with argon gas of 99.9% purity). Afterthe examination of 3 sintering temperatures (1020, 1050 and 1100 ºC), the sinteringtemperature at 1050 ºC illustrated the most desired results. The samples sintered underthese conditions were apparently intact, most of the interfacial part of the coatingwas found to be attached to the substrate surface irregularities and no single crackswere observed

Fe Doping in TiO₂ via Anodic Dissolution of Iron: Synthesis, Characterization, and Electrophoretic Deposition on a Metal Substrate

The tailored physical properties of TiO2 are of significant importance in various fields and, as such, numerous methods for modifying these properties have been introduced. In this study, we present a novel method for doping Fe into TiO2 via the anodic dissolution of iron. The optimal conditions were determined to be an application of 200 V to acetylacetone (acac)/EtOH medium for 10 min, followed by the addition of TiO2 to the solution, sonication for 30 min, stirring at 80 °C, and drying. The resulting powder was calcined at 400 °C for 3 h, and characterization was conducted using XRD, FTIR, TEM, and UV-vis. The synthesized powder revealed the successful doping of Fe into the TiO2 structure, resulting in a decrease in the optical band gap from 3.22 to 2.92 eV. The Fe-TiO2 was then deposited on a metal substrate via the electrophoretic (EPD) technique, and the weight of the deposited layer was measured as a function of the applied voltage and exposure time. FESEM images and EDX analysis confirmed that the deposited layer was nanostructured, with Fe evenly distributed throughout the structure