Preparation Of CuO Nanomaterials Using Different Methods And Their Photoelectric Properties

CuO have been extensively applied in many fields because of its excellent properties inphotics, electricity and magnetism, which has attracted much attention. Because the propertiesof CuO nanomaterials are influenced by morphology, crystal structure and size of CuOnanomaterials, designing and controlled synthesis of CuO semiconductor nanomaterials withnovel morphology and structure are of significance from both theoretical and practicalapplication point of view. In this thesis, the CuO nanowires,3-dimensional butterfly-like CuOand sphere-like CuO were synthesized by chemical precipitation, microwave-assisted methodand mild hydrothermal method, respectively. The morphology, structure and photoelectricalproperties of the synthesized CuO nanomaterials were studied by SEM, TEM, XRD, PL,UV-Vis, CV and I-t etc. The effects of various reaction conditions on the morphologies of theprepared CuO nanomaterials were discussed. The formation mechanisms of CuOnanostructures were proposed. The main content of this thesis is as follows:1. CuO nanowires were simply prepared by chemical precipitation combining withthermal decomposition at300℃, using CuCl2, K2CO3and NaOH as the raw materials, in thepresence of SDBS. The SEM and XRD results show that the product is monoclinic CuOnanowires with a diameter of around12nm. The calculated band gap energy is1.51eV basedon the UV-Vis absorption spectrum. Photoluminescence spectrum shows that the productemits purple-blue light. The series of control experiments show that the existance of K2CO3and NaOH plays an important role on the formation of CuO nanowires and the dosage ofSDBS also influences the morphology of the product.2.3-dimensional butterfly-like CuO with sheet-like hierarchical structures wassuccessfully synthesized through microwave-assisted method using CuCl2, K2CO3and NaOHas the raw materials. The formation mechanism of the butterfly-like CuO and thephotoelectric properties were studied. The cyclic voltammogram curve shows that thebutterfly-like CuO modified glass carbon electrode has obvious current response and theintensity increases with increasing the concentration of ascorbic acid and scanning rate. TheI-t curve indicates that the current response has a good linear relationship with theconcentration of ascorbic acid within certain range of concentration. The correlationcoefficient is0.9980, sensitivity41A mM-1cm-2, and limit of detection is0.5mol/L. Seriesof control experiments show that the crystal phases and surface property of the Cu2Cl(OH)3precursor, the kind of the basic salt precursor, the concentration of KOH and microwaveirradiation significantly influence the morphologies of the products. In addition, metaloxide-doped butterfly-like CuO were prepared by impregnation method. The results show thatthe photoluminescence intensity of the doped CuO changes with the kind of metal.3. Sphere-like CuO was synthesized by a mild hydrothermal method, using CuCl2and K2CO3used as the raw materials in the presence of SDBS. The analysis of SEM and XRDdemonstrates that the sphere-like CuO has a diameter of3~4m with rough surfaces and theaverage primary particle size is10.6nm. Photoluminescence spectra indicate that the productsin different atmospheres have similar emission peaks unless the intensity is different. Thecyclic voltammograms and I-t curve show that the sphere-like CuO modified glass carbonelectrode has obvious current response and it has a good linear relationship with theconcentration of ascorbic acid within certain range of concentration. The correlationcoefficient is0.9998, sensitivity30A mM-1cm-2, and limit of detection is0.3mol/L.Control experiments carried out in various conditions demonstrate that enough SDBS andreaction time are necessary for the formation of the spheres-like CuO with uniformmorphology and good dispersity. CuO with different morphology can be prepared bychanging the concentration of the reactants.