【作者】 闫丽丽；

【导师】 余颖；

【作者基本信息】 华中师范大学 ， 凝聚态物理， 2011， 硕士

【摘要】 Cu2O是一种金属缺位的直接禁带宽度的半导体材料,其禁带宽度大概为2.OeV左右,能够被可见光激发,因而能够有效利用太阳光,该材料在太阳能转换,传感器,光催化技术及电极材料等很多方面都有潜在的应用价值,因此成为一种备受关注的半导体纳米材料。本文以NaCl为阳极液,以NaOH为阴极液。采用铜阳极氧化法,直接在Cu基底上生长纳米结构Cu2O阵列薄膜。通过扫描电子显微镜(SEM),X-射线衍射(XRD),X-射线光电子能谱(XPS)等方法对所制备样品的结构形貌行进分析；通过紫外可见漫反射(UV-vis diffuser reflectance),开路电压(open ciruit)等测试方法对样品的光电化学性能进行表征。探索了Cu2O形貌的影响因素,并研究了Cu2O纳米结构薄膜材料的光催化杀菌性能。实验结果表明,通过该方法制备出的Cu2O呈p型特性,其禁带宽度为1.92 eV；反应时的面电流密度及表面活性剂对Cu2O形貌都有较大影响,通过对这两个试验参数的调控可以得到不同形貌的Cu2O：当采用CTAB作为表明活性剂时,随着面电流密度的增大,氧化亚铜的形貌从网状,片状到棒状进行转化。其中,由于棒状Cu2O的特殊形貌,使其具有最好的光催化杀菌性能；当面电流密度固定为10A/m2,阳极液中无任何表面活性剂时可以得到针尖状的Cu2O纳米阵列,当阳极液中的表面活性剂依次为CTAB、PVP、PEG时,分别可以得到纳米带状,枝桠状及纳米线状的Cu2O,通过对以上四种形貌Cu2O的开路电压分析,纳米线状的Cu2O具有最好的光电转换性能。此外,我们还研究了通过该种方法制备的p型Cu2O薄膜电极在电催化,光催化及光电共催化体系中对CO2的催化还原性能,并与通过简单沸煮法制备的n型Cu2O薄膜电极在以上三种体系中对CO：的催化还原性能进行对比,结果表明两种Cu2O薄膜电极在以上三种体系中对CO：都有一定的催化活性,其中在光电共催化体系中对CO2的催化活性最好。同时我们对各个体系的催化还原机理进行了研究,并对Cu2O薄膜电极在整个催化还原过程中的稳定性进行了分析。更多还原

【Abstract】 Cuprous oxide is a p-type semiconductor with a direct band gap of 2.0 eV and can be exitated by visible light. It has potential applications in solar energy conversion, electrode materials, sensors, and catalysis. So, cuprous oxide has become one of the hottest semiconductor nanomaterials.In this article, using NaCl as the anodic electrolyte and NaOH as cathodal electrolyte, Cu2O films by the method of copper anode oxidation have been prepared. They were characterized with the techniques of scanning electron microscopy, X-ray diffraction (XRD) pattern and X-ray photoelectron spectroscopy. Additionally, UV-Vis diffusion reflection spectroscopy (UV-Vis) and open ciruit were employed to record the photoelectrochemical properties of the nanostructures. Besides, we explored the effect of surfactants on the morphology of Cu2O thin film, and the sterilization property of the samples was also investigated.The results show that the sample we prepared through the method of copper anode oxidation is p-type Cu2O with the band gap of 1.97 eV. Both surface current density and surfactant have great impact on the morphology of Cu2O. When we use CTAB as the surfactant, with the increase of current density, the morphology of Cu2O can be nanonet, nanosheet and nanorod arrays respectively, among which nanorod cuprous oxide has the best activity in sterilization. When the surface current density was fixed to 10 A/m2, we can get needle-like, nanobelt, branch-like and nanowire Cu2O films when the anodic electrolyte contains a certain amount of CTAB, PVP, PEG respectively. And the nanowire Cu2O film has the best photoelectrochemical property.Additionally, the prepared Cu/Cu2O films were used as electrodes for catalytic reduction of CO2 in photochemical, electrochemical and photoelectrochemical system respectively. For comparison, n-type Cu2O through simple boiling process was also prepared. The results show that CH4 and C2H4 are the major hydrocarbon products in the above catalytic reduction systems and Cu2O thin film on Cu substrate has a higher selectivity for C2H4 production than blank copper electrode. The best yield for CO2 reduction is obtained in the photoelectrochemical system. The effect of electric field and visible light irradiation on the CO2 reduction was studied in detail. The stability of the Cu/Cu2O electrodes has been studied as well.更多还原