Hydrothermal Synthesis Of The Perovskite Lead Titanate2D Nanostructures And Their Application In The Catalytic Oxidation Of CO

Perovskite PbTiO3is a typical ferroelectric oxide. With regard to the nanostructures, more amounts of researches are focused on the perovskite PbTiO3one-dimensional (1D) nanostructures. Up to now, there is no report on the PbTiO32D nanostructures. In this thesis, single crystal PbTiO3perovskite nanosheets and sheet-assembled flower-like PbTiO3perovskite nanostructures are hydrothermally synthesized by selecting the modifiers and controlling the minerallizer concentration. The performance of the flower-like PbTiO3nanostructures as Pt-carrier on the catalytic oxidation of CO was also investigated. The obtained major achievements were listed as follow:(1) Single-crystal PbTiO3perovskite single-crystal PbTiO3nanosheets have been firstly hydrothermally synthesized under the assistance of NaNO3and KNO3, respectively. Due to the differences in electronegativity, Na+, K+ions are fastly bonded to (001) and (111) by preferential combination, respectively. As a consequence, the deposition of the lead titanate species on the (001) and (111) is suppressed, resulting in the formation of the single-crystal tetragonal perovskite PbTiO3nanosheets.(2) By hydrothermal method flower-like perovskite PbTiO3nanostructures have been successfully prepared through increasing the Pb/Ti ratio under high concentrations KOH. Pb2+ions substituted K+ions in layered structure K2Ti6O13that firstly formed in the early stage of hydrothermal treatment, resulting in peeling edge-connected TiO6-sheet which as a hard template led to synthesize self-assembled flower-like tetragonal perovskite PbTiO3.(3) Flower-like tetragonal PbTiO3as a catalyst support made the catalytic oxidation temperature of CO reduced to100℃. It reveals that the special structure, exposed faces, spontaneous ferroelectric polarization and the large surface areas of as-grown PbTiO3greatly improves the catalytic performance of Pt.