Preparation Of Antimony - Doped Tin Oxide Mesoporous Microspheres And Their Gas Sensitivity And Optical Properties

In this work, mesoporous undoped and antimony doped tin oxide(ATO) microspheres are synthesized by the easy and convenient solvothermal method. In the process, we firstly investigate the influences of precursor concentration, reaction solvent and surfactant on the morphology of samples; under the above optimized reaction conditions, the effect of Sb dopant amount on the morphology, crystal size, electrical conductivity, gas sensing and optical properties of samples. Furthermore, we explore the related mechanism. The results are summarized as follows:In this chapter, monodisperse mesoporous tin oxide microspheres with a high uniform in size are prepared via a facile preparation approach without complicated process. The influence of Sb dopant on morphology, crystal size, structure and electrical conductivity are characterized using Field emission scanning electron microscopy(FESEM), transmission electron microscopy(TEM), X-ray diffraction(XRD), Brunner-Emmett-Teller(BET) method, four-point probe and X-ray photoelectron spectroscopy(XPS), etc. These results show that, with the increasing dopant concentration, crystalline materials are achieved under all conditions, with only tetragonal rutile Sn O2(JCPDS Card NO.41-1445) diffraction peaks detected, and no other impurity phases in XRD peaks are found; the surface area decreases increases steadily with increasing Sb concentration, while the electrical resistivity and nanoparticles size of ATO powders shows a significant decrease just only by adding a really small amount of antimony. And as the Sb concentration increase, the sensitivity of gas sensors based on ATO increases. With the concentration of antimony in Sn O2 increasing to 10%(mol), the detection limit of as-prepared mesoporous ATO microspheres(~500 nm) sensor can reach as little as lower than one per million for HCHO, which make this material interesting for sensor devices.In order to test the optical performance of ATO mesoporous microspheres as Abstract fillers for transparent composite, the powder suspension is ground and casted on uniformly cast on the glass slide substrate by doctor-blade method. The influence of Sb concentration on the absorption, transmittance, reflectance, optical band gaps and solar-heat shielding ability is investigated. Moreover, the transmittance spectra of multilayer films of 5% doped ATO thin films indicate that the transparency in the visible and NIR spectrum is decreased with increasing the thickness of films. Although increasing the thickness of the coatings can improve the heat insulation capacity, the transmittance of the films decreases a lot. Compared with commercial F-doped tin oxide(FTO) and Sn-doped Indium oxide(ITO) glasses, the as-synthesized ATO-10 films show better solar-heat shielding ability. To test the solar shielding ability of ATO mesoporous microspheres as fillers for transparent composite, a simulated experiment is conducted, ATO-10 film shows further 1.5-4.5 °C temperature depression compared to those of ITO and FTO glasses, which is very attractive for energy saving applications.