Synthesis And Properties Of Low-dimensional Nanomaterials Of Molybdeum Oxide

The scientists around the world have interested in quasi-one-dimensionalnanomaterials, because of its unique feature electrical, optical and mechanicalperformance. In this paper, based on extensive literature research, we have explored thecontrolled growth of molybdenum trioxide nano-materials, photochromic, electrochromic,dye adsorption and two molybdenum oxide super-capacitors, lithium-ion transport andother aspects of exploration, and also obtained some interesting results. The main contentand results of this research papers are as follows:(1) we have prepared a large area of the quasi one-dimensional molybdenum oxideby thermal evaporation. This method is simple, direct, efficient, and it does not require anyspecial substrate and catalyst,which can be directly used to synthesize a large area of theMoO3nanosheets or nanowires arrays. We found that nanowires follows the VS growthprocess in the growth model by studied the growth of MoO3nanowires. Some factorshave a great influence on the final result in the experiment, such as the source temperature,the substrate temperature, the amount of oxygen.(2) The molybdenum trioxide has a unique layered structure, which particularlysuitable for a variety of ions into and prolapse. Therefore, MoO3nano-materials haspotential applications, such as photochromic, electrochromic, information display andstorage, color windows, sensors, smart camouflage applications and so on. In thephotochromic experiments, first we have done the UV light irradiation of photochromicexperiment,in which molybdenum trioxide was irradiated by UV light in the air, and laterin visible light experiment, MoO3nanomaterials was filled a certain amount of smallcations and then irradiated by visible light in the air. In electrochromic experiments, it wasfound to be it has very lower voltage-driven than reported in the literature to change thecolor. But in the appeal trial, we also found that the recovery color processing was failedby added the reverse voltage.In my opinion,it was caused by the lithium ions which lead tochanges in the structure with the expansion and that makes the ions can not escape, andanother reason is that the binding between the nanomaterials and the substrate is not verystrong by thermal evaporation, resulting in the materials fall off easily in the electrochromic experiment.(3) MoO3nanowires was made by thermal evaporation of molybdenum powder,using the carbon cloth as a template and added a certain amount of oxygen in the stove.And then it reduced to molybdenum dioxide in hydrogen atmosphere in a tube furnace. Bycomparing the SEM images of the reduction and nonrestored molybdenum oxide on thecarbon cloth, we found that the morphology has changed dramatically from sheet structureto fine-grained structure, and the surface area was increased. The reductiontemperature has a great impacton the morphology of the molybdenum oxide materials.Compared to molybdenum trioxide,the conductivity of the molybdenum dioxide has twoorders of magnitude higher conductivity, which its electron mobility is close to themetal. We know that the conductivity, surface area, stability is the main deciding factor inthe super capacitor. And just molybdenum dioxide nanosheets meet these requirements. Soin this paper we have made the molybdenum dioxide to be super capacitor.(4) The mixture of the molybdenum dioxide nanowires and elemental molybdenumwas grown on the silicon substrate by thermal evaporation, and it oxidized tomolybdenum trioxide in a muffle furnace. During the growth of the molybdenum oxidematerials, we found that the evaporation source temperature, the substrate temperature andthe amount of oxygen in the chamber have a great impact on their morphology. In theSEM, TEM image analysis, the nanowires was found that the nanowires were depositedby some accumulation nanoparticles. With time and temperature increased, each particlecan grow into a whiskers, and the whisker crystal grow to another small whiskers, lastthe nanomaterials looks like the tree and flower. Because of its unique structure and largesurface area, we have done a physical adsorption experiment, through magnetic stirring amixture of nano-materials and fuel, the color fades.