Mesoporous Zirconium Oxide And Nano Preparation And Characterization Of Carbon Composite Material

Zirconia (ZrO2) possesses unique properties such as redox activities, high ion-exchange capacity and abundant oxygen vacancies, which made it become an attractive material for application in catalysis and separation. Carbon nanotubes (CNTs) and graphene, due to their unique electrical property, high thermal conductivity and strong mechanical strength, have been considered as powerful reinforcement in metal oxides aiming at improving electrical conductivity, thermal and mechanical properties. In this thesis, we explore a new approach to synthesis of mesoporous ZrO2with high thermal stability, and further study is to synthesis and characterization of mesoporous ZrO2/CNTs composites and ZrO2/graphene composites. The main achievements of the research are listed below.Mesoporous ZrO2samples with high thermal stability were synthesized by hydrothermal homogeneous precipitation method using an anionic surfactant as template. In this method, sodium dodecyl benzene sulfonate (SDBS) not only functioned as mesoporous structure-directing agent but also functioned as mesoporous structure stabilizer with the sulfonic groups converted to SO42-after calcination. The samples were characterized with transmission electron microscopy (TEM), nitrogen adsorption-desorption, X-ray diffraction (XRD), and fourier transform infrared (FT-IR). It was found that as-made ZrO2have worm-like mesoporous structure after calcination at500℃, they are existing in tetragonal phase even calcinated at600℃, indicative of good thermal stability.Mesoporous ZrO2/CNTs composites were fabricated by a simple method through hydrothermal process using cetyltrimethylammonium bromide (CTAB) as structure-directing agents. TEM, nitrogen adsorption-desorption, XRD and FT-IR analysis techniques were used to characterize the samples. It was found that bimodal mesoporous ZrO2existing in cubic phase overlaid on the surface of CNTs. The mesoporous-nanotube composites possessed properties such as one-dimension hollow structure, high surface area (312m2/g), bimodal mesoporous structure (3.18nm and12.4nm).ZrO2/graphene composites have been successfully synthesized via decompositoin of ZrOCl2·6H2O in a water-isopropanol system with dispersed graphite oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+and the deoxygenation of GO at the same time. TEM, XRD and FT-IR analysis techniques were used to characterize the samples. It was found that graphene nanosheets are fully coated with ZrO2and the ZrO2had tetragonal phase.