硒化铜膜与二氧化钛纳米管阵列的制备及性质研究

发布时间：2018-02-08 18:58

  本文关键词： 花状硒化铜 话筒状Cu2Se膜 TiO2纳米管阵列 光降解活性 气体传感性　出处：《天津理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：最近一些年来,有序的微/纳米材料因其在许多领域存在潜在应用而受到很大注意。硒化铜是一种重要的p型半导体,带隙能为1.2-2.3 e V,有多种组成(Cu Se、Cu2-xSe、Cu2Se、Cu2Se3和Cu5Se4)和晶相(立方、正方、正交和单斜),可广泛用于催化剂、超离子导体和太阳能电池等。它们可由多种方法合成,如水热法、溶剂热法、化学沉积法、加热铜和硒粉混合物及微波辅助法等。然而,据我们所知,目前还没有关于由层状超薄纳米片组装成的话筒状Cu2Se微结构的合成及室温条件下一步合成硒化铜纳米片阵列结构的报道。Ti O2纳米结构光催化剂不仅活性和化学稳定性较高,且成本低、无毒性,还具有抗光腐蚀性,因此受到了广泛关注。因Ti O2纳米管阵列结构拥有较高的比表面积也就是活性较高,且光催化反应以后容易从多相反应体系中回收再利用,因此研究Ti O2纳米管阵列薄膜近年来很热门。本文采用比较简单的合成方法制备了一系列硒化铜膜及Ti O2纳米管阵列薄膜,并研究其性质,具体内容包括:1.首次采用一步法在常温常压下在铜箔上制备了高度有序且分布均匀的具有纳米片状次级结构的花状硒化铜,对其进行了一系列的表征且首次研究了其对多种气体的传感性能。研究发现它对丙酮的气体传感性是最好的,且响应快速,响应时间4s,恢复时间为5s,因此,它将来可能成为很好的气体传感材料。2.将棒状的Cu(OH)2前驱体放置在Se2-溶液中,室温下反应4小时,成功制备高度有序的立方晶相的由超薄纳米片组成的话筒状Cu2Se微纳米结构。以随时间变化的形貌演变为基础,研究其形成机理。结果表明,话筒状Cu2Se微纳米结构的形成过程涉及到奥斯特瓦尔德熟化、沉淀转化、硒化亚铜的取向生长及自组装等过程。由紫外-可见漫反射吸收光谱得出它的带隙能为2.03 e V。3.用阳极氧化法在由氟化铵、乙二醇、3 vol.%H2O和7 vol.%甲酰胺组成的电解液中成功制备了Ti O2纳米管阵列膜,并且在400℃下煅烧三小时就可以得到锐钛矿相Ti O2。这种Ti O2纳米管阵列膜表现出了对紫外光和可见光都有很好的吸收能力,它的带隙为2.74 e V。而这种低带隙能很可能是由于Ti3+(氧空位)引起的。此外,还观察到1.7 e V的亚带隙能,其主要归因于不可忽略的N掺杂(9.87 At.%)。研究了反应条件对Ti O2纳米管管长和管径的影响,并制备了一系列具有不同管长(管径相近)和管径(管长相近)的样品,研究了不同管长和管径对其光催化活性的影响。发现外加电压对Ti O2纳米管阵列的管长和管径都有很明显影响。管径的变化对其活性影响较小,而当管长从0.57增加至2.03?m时,光降解率明显提高。另外自由基的捕获实验结果表明?OH是用于光降解罗丹明B主要的活性物。此外,光生空穴活动也参与了部分光降解过程。
[Abstract]:In recent years, ordered micro- / nanomaterials have attracted considerable attention for their potential applications in many fields. Copper selenide is an important p-type semiconductor with a band gap energy of 1.2-2.3 e V, with a variety of composition and crystalline phases (cubic, Cu5Se4 and Cu2Se2Se3, Cu2Se2Se3 and Cu5Se4). Square, orthogonal and monoclinic, widely used in catalysts, superconductors, solar cells, etc. They can be synthesized by many methods, such as hydrothermal method, solvothermal method, chemical deposition method, etc. Heating copper and selenium powder mixtures and microwave-assisted methods, etc. However, as far as we know, Up to now, there are no reports on the synthesis of microstructures of Cu2Se microstructures assembled from layered and ultrathin nanowires and the synthesis of nanocrystalline arrays of copper selenides at room temperature. The photocatalysts of TIO _ 2 nanostructures not only have high activity and chemical stability, but also have high chemical stability. Due to its low cost, non-toxicity and photo-corrosion resistance, it has attracted wide attention because of its high specific surface area, I. e., high activity, due to the high specific surface area of TIO _ 2 nanotube arrays. And the photocatalytic reaction is easy to recover and reuse from the multiphase reaction system. In this paper, a series of copper selenide films and TIO 2 nanotube array films have been prepared by a simple synthesis method, and their properties have been studied. For the first time, a highly ordered and well-distributed flower-like copper selenide with nanoscale secondary structure was prepared on copper foil by one-step method at room temperature and atmospheric pressure. A series of characterizations were carried out and its sensing performance to various gases was studied for the first time. It was found that its gas transfer to acetone was the best, and the response time was 4 s, and the recovery time was 5 s. It could be a good gas sensing material in the future. Put the rod-like Cu(OH)2 precursor in the solution of Se2- and react at room temperature for 4 hours. The highly ordered cubic Cu2Se microstructures consisting of ultrathin nanocrystals were successfully prepared. The formation mechanism of the microstructures was studied on the basis of the morphology evolution over time. The formation process of microstructures of microphone Cu2Se involves the ripening and precipitation transformation of Ostwald. Orientation growth and self-assembly of cuprous selenide. The band gap energy of copper selenide was 2.03 e V. 3 by UV-Vis diffuse reflectance spectroscopy. TIO 2 nanotube array films were successfully prepared in electrolyte composed of ethylene glycol 3 vol.%H2O and 7 vol.% formamide. Anatase phase TIO _ 2 can be obtained by calcining at 400 鈩，

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