Abstract: Semiconducting oxides in one-dimensional shape have stimulated a great interest for applications in optics and sensor fields. One-dimensional nano-SnO2 with rutile structure, as an n-type semiconductor with a wide bandgap, is well known for its excellent photoelectric property, gas sensitivity and humid sensitivity. Recently, it has been reported that one-dimensional tin oxide materials, such as tin oxide nanobelts, can be synthesized by high-temperature oxidation method, a convenient and fast method with inexpensive experimental equipment. However, its synthesis mechanism and the growth process of tin oxide nanobelts in this method are still unclear. In this research, one dimensional nano-SnO2 is synthesized from metal-reactive assistant reaction system by high-temperature oxidation method, and their structure, morphology and composition are characterized by using X-ray diffraction (XRD), transmission electron microscope(TEM) and scanning electron microscope(SEM). The affecting factors and mechanism of the nano-SnO2 formation are discussed. The results show that they are smooth and uniform along the fiber axis, and had a high crystalline; and they are formed by means of the fusion and coalescence between neighboring SnO2 nanoparticles. A new mold, liquid-solid pressure constraint rapid cooling oxidation model is built to describe the growth mechanism of the one dimensional nano-SnO2, which is different from the known typical nano-SnO2 growth mechanisms, such as vapor-liquid-solid mechanism, oxide-assisted growth mechanism, vapor-solid mechanism, solution liquid-solid mechanism and so on. This method also applies to synthesizing other metallic oxide nanomaterials.

Key words: Growth mechanism, High-temperature oxidation, Nanowires, Stannic oxide