Control Synthesis Of Stannate Pyrochlores Micro/Nano Materials And Their Sensing Properties

Uniform and mondispersed ZnSnO3 cubic crystallites with different particle size have been synthesized via simple and facile methods. Various architectures of ZnSnO3 were prepared by a ligand-assisted hydrothermal route, and a series of complexing agents were chosen as organic ligands to controlled synthesize ZnSnO3 architectures, and some ZnSnO3 nano/microstructures, such as cubic cages, nanoparticles self-assemble microball, nanowire, block self-assemble microball, hexagon, block self-assemble octahedron were obtained. The structures and optical properties of as-prepared products were thoroughly characterized using X-ray diffraction (XRD), thermogravimetry-differential thermal analysis (TG-DTA), Brunner-Emmett-Teller (BET) method, X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), transmission Uniform and monodisperse ZnSnO3 cubic crystallites were prepared via a solution process involving the reaction of zinc sulfate and sodium stannate at a reaction temperature as low as 0冞C without any surfactant. The size was readily controlled from 40 to 600 nm by varying the reaction temperature. The possible formation mechanism of cubic crystallites was attributed to a nucleation assembly process. The as-fabricated sensors based on ZnSnO3 cubic crystallites showed high sensitivity, fast response, and short recovery times toward HCHO gas. And as the particle-size of ZnSnO3 cubic crystallites decrease, the sensitivity of gas sensors based on them increases and the recovery time shorten rapidly. The detection limit of ZnSnO3 cubic crystallites sensor can reach as little as lower than one per million for HCHO. The performance of a home-built ZnSnO3 cubic crystallites sensor was even better than the competing SnO2 and In2O3 sensor, making this material interesting for sensor devices.Various architectures of ZnSnO3 were prepared by a ligand-assisted hydrothermal route such as: cubic cages, nanoparticles self-assemble microball, nanowire, block self-assemble microball, hexagon, block self-assemble octahedron etc. Their gas sensing properties also have been tested, we found that nanowire have the best gas sensing property. There are two reasons, on the one hand, nanowire have smaller particle-size and larger surface area, on the other hand, nanowire is one-dimensional material, this will help to transfer the electron.A facile and general method had been taken to synthesis a kind of colloidal MSnO3 (M = Zn, Mg, Cd, Mn, Cu) nanocrystals with no surfactant and template. Their gas sensing properties also have been tested; we found that the best working voltage of gas sensor based on CdSnO3 colloidal nanocrystals is lower than others, the lower working voltage is helpful to application. In addition, gas sensor based on CdSnO3 colloidal nanocrystals has higher sensitivity for ethanol and better selectivity. It is feasible that the CdSnO3 colloidal nanocrystals-based sensor was used as a detector of drinking for drivers.