本文關(guān)鍵詞： 花狀硒化銅 話筒狀Cu2Se膜 TiO2納米管陣列 光降解活性 氣體傳感性　出處：《天津理工大學(xué)》2015年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：最近一些年來(lái),有序的微/納米材料因其在許多領(lǐng)域存在潛在應(yīng)用而受到很大注意。硒化銅是一種重要的p型半導(dǎo)體,帶隙能為1.2-2.3 e V,有多種組成(Cu Se、Cu2-xSe、Cu2Se、Cu2Se3和Cu5Se4)和晶相(立方、正方、正交和單斜),可廣泛用于催化劑、超離子導(dǎo)體和太陽(yáng)能電池等。它們可由多種方法合成,如水熱法、溶劑熱法、化學(xué)沉積法、加熱銅和硒粉混合物及微波輔助法等。然而,據(jù)我們所知,目前還沒(méi)有關(guān)于由層狀超薄納米片組裝成的話筒狀Cu2Se微結(jié)構(gòu)的合成及室溫條件下一步合成硒化銅納米片陣列結(jié)構(gòu)的報(bào)道。Ti O2納米結(jié)構(gòu)光催化劑不僅活性和化學(xué)穩(wěn)定性較高,且成本低、無(wú)毒性,還具有抗光腐蝕性,因此受到了廣泛關(guān)注。因Ti O2納米管陣列結(jié)構(gòu)擁有較高的比表面積也就是活性較高,且光催化反應(yīng)以后容易從多相反應(yīng)體系中回收再利用,因此研究Ti O2納米管陣列薄膜近年來(lái)很熱門(mén)。本文采用比較簡(jiǎn)單的合成方法制備了一系列硒化銅膜及Ti O2納米管陣列薄膜,并研究其性質(zhì),具體內(nèi)容包括:1.首次采用一步法在常溫常壓下在銅箔上制備了高度有序且分布均勻的具有納米片狀次級(jí)結(jié)構(gòu)的花狀硒化銅,對(duì)其進(jìn)行了一系列的表征且首次研究了其對(duì)多種氣體的傳感性能。研究發(fā)現(xiàn)它對(duì)丙酮的氣體傳感性是最好的,且響應(yīng)快速,響應(yīng)時(shí)間4s,恢復(fù)時(shí)間為5s,因此,它將來(lái)可能成為很好的氣體傳感材料。2.將棒狀的Cu(OH)2前驅(qū)體放置在Se2-溶液中,室溫下反應(yīng)4小時(shí),成功制備高度有序的立方晶相的由超薄納米片組成的話筒狀Cu2Se微納米結(jié)構(gòu)。以隨時(shí)間變化的形貌演變?yōu)榛A(chǔ),研究其形成機(jī)理。結(jié)果表明,話筒狀Cu2Se微納米結(jié)構(gòu)的形成過(guò)程涉及到奧斯特瓦爾德熟化、沉淀轉(zhuǎn)化、硒化亞銅的取向生長(zhǎng)及自組裝等過(guò)程。由紫外-可見(jiàn)漫反射吸收光譜得出它的帶隙能為2.03 e V。3.用陽(yáng)極氧化法在由氟化銨、乙二醇、3 vol.%H2O和7 vol.%甲酰胺組成的電解液中成功制備了Ti O2納米管陣列膜,并且在400℃下煅燒三小時(shí)就可以得到銳鈦礦相Ti O2。這種Ti O2納米管陣列膜表現(xiàn)出了對(duì)紫外光和可見(jiàn)光都有很好的吸收能力,它的帶隙為2.74 e V。而這種低帶隙能很可能是由于Ti3+(氧空位)引起的。此外,還觀察到1.7 e V的亞帶隙能,其主要?dú)w因于不可忽略的N摻雜(9.87 At.%)。研究了反應(yīng)條件對(duì)Ti O2納米管管長(zhǎng)和管徑的影響,并制備了一系列具有不同管長(zhǎng)(管徑相近)和管徑(管長(zhǎng)相近)的樣品,研究了不同管長(zhǎng)和管徑對(duì)其光催化活性的影響。發(fā)現(xiàn)外加電壓對(duì)Ti O2納米管陣列的管長(zhǎng)和管徑都有很明顯影響。管徑的變化對(duì)其活性影響較小,而當(dāng)管長(zhǎng)從0.57增加至2.03?m時(shí),光降解率明顯提高。另外自由基的捕獲實(shí)驗(yàn)結(jié)果表明?OH是用于光降解羅丹明B主要的活性物。此外,光生空穴活動(dòng)也參與了部分光降解過(guò)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，

本文編號(hào)：1496038