| Low-dimensional nanomaterials possess significantly different physical, chemical,biological properties with bulk materials, is increasingly becoming a hot area of nanotechnology research.Oxide semiconductor nano-materials have been intensively investigated due to anticipated applications in many areas such as lithium ion electrode materials, solar cells, light degradation, photo catalysis, chemical sensors, cathode emitters of the field emission device and so forth. In this paper, the preparation, magnetism, luminescence, sensor, field emission and other properties of ZnO and SnO2 nano-structures has been systematic studied. The main research content and innovation points are as follows:1.Synthesis and physical properties research of Cu-doped SnO2 nanowires.The Cu-doped SnO2 nanowires were synthesized by thermal chemical vapor transport method. The obtained samples were investigated by X-ray diffraction (XRD),scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectroscopy (EDS) and photoluminescence (PL) spectra. The temperature dependence photoluminescence characteristics of the Cu-doped SnO2 nanowires show that two luminescence bands centered at 590 nm and 630 nm, and a right shoulder at 677nm. Field emission measurements demonstrated that the Cu-doped nanobelts possessed good performance with a turn-on field of～2.9 V/μm and a threshold field of～4.8 V/μm. Although the NWs consist of only nonmagnetic elements, room-temperature ferromagnetism is observed and its origin is attributed to both the structure defects and strong p-d ferromagnetic coupling between the local magnetic moment of Cu2+ and the polarized valence electrons of the surrounding oxygen based on first-principles calculations.2.Synthesis and physical properties research of Cu-doped ZnO nanosheets.Triangle-like ZnO nanosheets have been synthesized via conventional thermal evaporation method using CuO as catalyst. The obtained samples were investigated by XRD,SEM, HRTEM, EDS and PL etc.The great influences of Cu catalyst on the morphology of the obtained ZnO nanostructures were investigated. The field emission measurements confirmed that the ZnO nanosheets possessed good performance with a turn-on field of 3.1 Vμm-1 and a field enhancement factor of 3250,which have promising application as a competitive cathode material in FE microelectronic devices.Room temperatures ferromagnetism has been observed in the triangle-like ZnO nanosheets, although the products consist of only nonmagnetic elements.The magnetism origin has been studied.3.Catalysis research of CuO in the preparation of oxide nanomaterials.Other growth conditions are consistent, except that adding CuO powder into the reactant mixture powder, which is supposed to play a critical role in the formation of ZnO,SnO2, In2O3 nanomaterials.We have successfully synthesized ultralong comb, belt and branch-like ZnO, Zigzag and belt like SnO2,and In2O3 structure, reach to about 1.5cm in length.The growth mechanism of the ultralong structures and the catalytic behavior of the copper have been discussed.The humidity sensor based on a single SnO2 zigzag belts has been researched.4.Synthesis and field emission properties of oxide nanomaterials.Field emission properties depend on the work function of the material and the field enhancement factor. Both ZnO and SnO2 are good field emission cathode materials, their nanostructures with abundant surface morphological and large field enhancement factor. We have successfully synthesized various ZnO,SnO2 and Sn-doped ZnO nanostructures.Obtained samples were investigated by XRD,SEM, HRTEM,and PL etc.The field emission measurements confirm that these structures possessed good performance with lower turn-on field and threshold field,higher field emission current density, which have promising application as a competitive cathode material in FE microelectronic devices.
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