Controllable Preparation And Performance Studies Of Zinc Oxide And Tungsten Oxide Micro/nano Materials

Micro/nanomaterials have a wide range of applications in catalysis,sensing,energy storage due to the unique physical and chemical properties,so the preparation of novel metal oxide nanomaterials,the morphology of crystal size and dimension,growth mechanisms have been widely studied in this field.Therefore,these studies can be helpful to further study the relationship between the micro-nanostructures and the function of materials,making efficient use of micro/nano-structure and increasing its industrialization.In this paper,it mainly concentrates on the modification of structure and composition of semiconducting metal oxides?ZnO and WO₃?micro/nano materials,the preparation of novel ZnO and WO₃ nanomaterials,the possible formation mechanisms,and the catalytic degradation performance or gas sensitive activity.1.Three dimensional?3D?hierarchical spherical-like ZnO nanostructures were synthesized through a facile hydrothermal method using distilled water and glycerol as the main solvent.The as-prepared nanostructures with thickness of 5 nm were assembled by large amounts of nanosheets.Based on a series of time-dependent experiments and characterizations,the self-assembly mechanism related to nucleation-dissolving-recrystallization was proposed for the 3D spherical-like ZnO nanostructures.The gas sensing performances of the products have also been investigated in detail,and these spherical-like ZnO nanostructures exhibited an excellent gas sensing performance to acetone and the sensor shows a quick response?8 s?and short recovery?2 s?time.2.Dysosma pleiantha-like hierarchical ZnO nanostructures?DPHZNs?consisting of nanosheets have been successfully obtained by simple and environmentally friendly hydrothermal route.The as-prepared DPHPZNs with thickness of 10-20nm were assembled by large amounts of nanosheets.The structure,morphology and size were characterized by X-ray powder diffraction?XRD?,scanning electron microscopy?SEM?et al.Furthermore,the photocatalytic activity of the obtained DPHPZNs was investigated for the degradation of RhB.The obtained DPHPZNs exhibit excellent photocatalytic efficiency and the advantages of this structure in the photocatalytic degradation of RhB were analyzed.3.We have successfully synthesized three-dimensional camellia-like WO₃·0.33H2O architectures via EDTA-assisted hydrothermal route,and EDTA played an important role in the formation of this unique structure.A possible formation mechanism was nucleation-dissolving-recrystallization self-assembly.WO₃·0.33H2O with camellia-like structure exhibit the higher photocatalytic activity in the degradation of MB.Our results indicate that the as-prepared product shows great potential as visible-light-driven photocatalyst.4.Hierarchical double-shell WO₃ microspheres?HDS-WO₃?have been successfully obtained through direct precipitation method formed by metal salts as the sacrificial templates.The products were characterized by X-ray diffraction?XRD?,and the morphology was investigated by scanning electron microscopy?SEM?and transmission electron microscopy?TEM?.In addition,the HDS-WO₃ microspheres were analyzed by the Thermogravimetric?TG?and Brunauer-Emmett-Teller?BET?analysis.This three-dimensional architectures structure has a larger surface area,mesoporous structure and higher crystallinity,which is much higher than other structures.Meanwhile,the obtained HDS-WO₃ exhibits excellent photocatalytic efficiency.