二氧化钛基纳米复合物的制备及其光催化与光电性能

发布时间：2018-04-20 23:02

本文选题：二氧化钛 + 石墨烯　；参考：《广东工业大学》2017年硕士论文

【摘要】：作为一种半导体,二氧化钛(TiO_2)因其独特的性能已成为现代材料系列中最引人瞩目的材料,受到了众多物理化学家、材料科学家和工程师的关注。本论文用石墨烯(GR)、聚苯胺(PANI)及聚吡咯(PPy)对TiO_2进行改性,分别制备了GR-TiO_2纳米复合物、PANI-GR-TiO_2纳米复合物以及PPy-Ti O_2纳米复合物,并对它们的光催化性能和光电性能进行了研究。主要工作如下:(1)以FTO导电玻璃为基底,采用水热法和旋涂法制备出GR修饰的TiO_2纳米棒膜状复合物。通过场发射扫面电子显微镜表征了所制备样品的形貌,用X射线衍射仪和拉曼光谱仪分析了样品的结构,结果表明,在棒状金红石型TiO_2的表面负载了一层透明的GR薄膜;利用紫外可见分光光度计研究了样品的光学性质,结果表明,GR的加入拓宽了TiO_2的光吸收范围;同时,还探索了所制备的样品分别在紫外光和模拟太阳光照射下的光催化性能,结果表明,GR的加入增强了TiO_2的光催化性能;另外,还组装了FTO-GR-TiO_2-FTO器件对GR-TiO_2纳米复合物的UV光电性能进行了测试,从而进一步说明GR的引入不仅增强了TiO_2对光的吸收,更为传输TiO_2的光生电子提供途径,抑制了光生电子-空穴对的重组,增强了TiO_2的光催化性能。(2)利用原位化学沉积法在GR修饰的TiO_2纳米棒膜状复合物表面沉积PANI纳米线薄膜,并组装了FTO-PANI-GR-TiO_2-FTO器件。通过场发射扫描电子显微镜、拉曼光谱仪、紫外可见分光光度计以及荧光光谱仪对样品的形貌、结构、光学性质进行了表征,结果表明,PANI成功负载在GR-TiO_2纳米复合结构表面,且PANI的加入增强了TiO_2对光的吸收;通过电化学工作站对复合物的光电性能进行了研究,发现PANI的加入增强了TiO_2对UV的响应,进一步提高了TiO_2的光电性能,PANI-GR-Ti O_2纳米复合物在紫外探测及传感领域有一定的应用价值。(3)利用原位化学沉积法在所制备的金红石型TiO_2纳米棒上负载了一层PPy纳米线薄膜,控制沉积次数,制备了PPy厚度不同的PPy-TiO_2纳米复合物,并组装了FTO-PPy-TiO_2-FTO器件。通过场发射扫描电子显微镜和拉曼光谱仪分析证实了金红石型TiO_2纳米棒顶端成功被PPy纳米线薄膜覆盖;通过紫外可见吸收光谱和光致发光光谱研究了复合物的光学性质,证明PPy的加入确实能够增强纯TiO_2对紫外光的吸收,且当沉积次数为3次时增强效果最佳;通过电流时间曲线和交流阻抗曲线研究了复合物的光电性能,结果表明PPy的引入增强了器件对紫外光的响应,且沉积次数为3次时光电响应效果最好。
[Abstract]:As a semiconductor, Titanium dioxide (TiO-2) has become the most attractive material in modern material series because of its unique properties. It has attracted the attention of many physical chemists, material scientists and engineers. In this paper, TiO_2 was modified by graphene, Polyaniline (pani) and polypyrrole (PPyR). The GR-TiO_2 nanocomposites, PANI-GR-TiO2 nanocomposites and PPy-Ti O _ 2 nanocomposites were prepared, and their photocatalytic and photoelectric properties were studied. The main work is as follows: (1) GR-modified TiO_2 nanorods were prepared by hydrothermal method and spin-coating method on FTO conductive glass substrate. The morphology of the samples was characterized by field emission scanning electron microscope. The structure of the samples was analyzed by X-ray diffraction and Raman spectroscopy. The results showed that a transparent gr film was deposited on the surface of rod-like rutile TiO_2. The optical properties of the samples were studied by UV-Vis spectrophotometer. The results show that the addition of gr broadens the optical absorption range of TiO_2, and also explores the photocatalytic properties of the prepared samples under ultraviolet and simulated sunlight, respectively. The results show that the addition of gr enhances the photocatalytic properties of TiO_2, and the UV photovoltaic properties of GR-TiO_2 nanocomposites are tested by assembled FTO-GR-TiO_2-FTO devices, which further shows that the introduction of gr not only enhances the absorption of light by TiO_2, but also enhances the photocatalytic properties of TiO_2. The photoelectron transport of TiO_2 provides a way to inhibit the recombination of photogenerated electron-hole pairs and enhance the photocatalytic performance of TiO_2. (2) PANI nanowire films were deposited on gr modified TiO_2 nanorods by in situ chemical deposition. The FTO-PANI-GR-TiO_2-FTO device is assembled. The morphology, structure and optical properties of the samples were characterized by field emission scanning electron microscope, Raman spectrometer, UV-Vis spectrophotometer and fluorescence spectrometer. The results showed that pani was successfully loaded on the surface of GR-TiO_2 nanocomposite structure. The addition of PANI enhanced the optical absorption of TiO_2, and the photoelectric properties of the composite were studied by electrochemical workstation. It was found that the addition of PANI enhanced the response of TiO_2 to UV. The photoelectrical properties of TiO_2 were further improved. PANI-GR-TiO _ 2 nanocomposites have certain application value in the field of UV detection and sensing. A layer of PPy nanowire films were deposited on rutile TiO_2 nanorods by in-situ chemical deposition. PPy-TiO_2 nanocomposites with different PPy thickness were prepared by controlling the deposition times, and FTO-PPy-TiO_2-FTO devices were assembled. The results of field emission scanning electron microscopy and Raman spectrometer show that the top of rutile TiO_2 nanorods is successfully covered by PPy nanowire films, and the optical properties of the composites are studied by UV-Vis absorption spectra and photoluminescence spectra. It is proved that the addition of PPy can enhance the absorption of ultraviolet light by pure TiO_2, and the best enhancement effect is obtained when the deposition times are 3 times, and the optoelectronic properties of the composite are studied by means of current time curve and AC impedance curve. The results show that the introduction of PPy enhances the response of the device to ultraviolet light, and the photoelectric response is the best when the deposition times are 3 times.
【学位授予单位】：广东工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ134.11;TB383.1

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