水分散二氧化钛纳米粒子在太阳能转化领域的应用研究

发布时间：2018-03-05 05:19

本文选题：TiO_2纳米晶　切入点：能量转化　出处：《吉林大学》2017年硕士论文　论文类型：学位论文

【摘要】：TiO_2具有无味、无毒、挥发性差、热稳定性好、介电常数高、钛源广泛、制备方法多样、简单易行、应用面广等诸多优点,常被用作光催化剂,本论文旨在利用TiO_2自身的优良性质将其应用在聚合物/纳米晶杂化太阳能电池及光催化产氢领域实现太阳能的转化。具体来讲,本论文的工作归纳为如下两个方面。第一部分的工作是:将高性能的TiO_2作为聚合物/纳米晶杂化太阳电池的阴极界面修饰层,在杂化太阳能电池的领域实现太阳能的转化。TiO_2本身具有电子迁移率高,透光性好,能有效的阻挡空穴的优点,因此常被用作阴极界面修饰层。以往传统作为阴极界面修饰层的TiO_2纳米晶都是利用Sol-gel法制备的,该方法制备的TiO_2结晶性差,所以造成导电性差,同时还对湿度敏感,在高湿度条件下不能使用,所以针对以上的缺点利用我们所制备出来的小尺寸的TiO_2纳米晶做为阴极界面修饰层,由于其表面具有大量羟基,成膜后具有超亲水性,退火后结晶性好,所以该器件导电性较之前明显提高,并且抗湿性能也大大提升,通过优化器件得到了5.53%的电池效率,这也是目前所报道的水相操作的聚合物/纳米晶杂化太阳能电池的最高效率。第二部分的工作是:将高性能的TiO_2作为光催化剂分解水产氢,在光催化产氢领域实现太阳能的转化。由于TiO_2自身的优良性质常被用作光催化剂,但其禁带宽度较宽(3.2 eV),因此对可见光利用较少,TiO_2吸收能量后产生光生电子和空穴,电子和空穴还会很快复合导致降低光催化效率和产氢效果,基于以上两种原因,为提高材料对太阳能的利用率和产氢效率,常将TiO_2进行改性提高,例如:加入给电子体(EDTA、甲醇、乙醇、乳酸、CN-和甲醛)、加入碳酸盐、负载贵金属、掺杂离子、与其它材料复合等方法,本章是利用TiO_2分别与氧化石墨烯(GO)和将其还原后得到的石墨烯(G)进行复合,得到TiO_2/GO、TiO_2/G两类复合材料进行光催产氢性能研究,并对氧化石墨烯和石墨烯进行了产氢对比,并且调节了石墨烯的质量分数,其中是利用还原的石墨烯并且其占TiO_2质量的1%时产氢效果最佳。综上所述,我们通过利用自身性质优良的TiO_2纳米晶,一方面将其应用在水相操作的聚合物/纳米晶杂化太阳能电池中作为阴极界面修饰层,提高器件导电效率及抗湿性能,优化器件效率,另一方面将其与导电性良好的石墨烯复合制得复合光产氢催化剂,实现对太阳能的利用和转化,对未来能源和可持续发展贡献绵薄之力。
[Abstract]:TiO_2 has many advantages, such as tasteless, non-toxic, poor volatility, good thermal stability, high dielectric constant, wide titanium source, various preparation methods, simple and easy to be used, and so on, so it is often used as photocatalyst. The purpose of this thesis is to make use of the excellent properties of TiO_2 to realize the conversion of solar energy in polymer / nanocrystalline hybrid solar cells and photocatalytic hydrogen production. The work of this thesis is summarized as follows. The first part is to use high-performance TiO_2 as the cathode interface modification layer of polymer / nanocrystalline hybrid solar cells. In the field of hybrid solar cells, the conversion of solar energy. TiOs _ 2 has the advantages of high electron mobility, good light transmittance and effective hole-blocking. In the past, TiO_2 nanocrystals, which were used as cathode interfacial modification layers, were prepared by Sol-gel method. The TiO_2 prepared by this method has poor crystallinity, which results in poor conductivity and humidity sensitivity. It can't be used in high humidity condition, so we use the small size TiO_2 nanocrystalline prepared by us as cathode interface modification layer, because of its surface has a large amount of hydroxyl, the film has super hydrophilicity. After annealing, the electrical conductivity of the device is improved obviously, and the humidity resistance is greatly improved. By optimizing the device, the battery efficiency of 5.53% is obtained. This is also reported as the highest efficiency of aqueous polymer / nanocrystalline hybrid solar cells. The second part of the work is to use high-performance TiO_2 as photocatalyst to decompose aquatic hydrogen. The conversion of solar energy in the field of photocatalytic hydrogen production is realized. Because TiO_2 itself is often used as photocatalyst, but its band gap is wider than 3.2eV ~ (-1), the visible light can be used less energy to absorb energy and generate photogenerated electrons and holes. Electrons and holes can also quickly compound to reduce photocatalytic efficiency and hydrogen production efficiency. For these two reasons, TiO_2 is often modified to improve the utilization of solar energy and hydrogen production efficiency of materials. Ethanol, lactic acid CN- and formaldehyde, carbonate, loaded precious metals, doped ions, and other materials are added. In this chapter, TiO_2 is used to combine with graphene oxide (GOO) and graphene oxide (GG), respectively. Two kinds of composites, TiO-2 / Goo / TiOG, were obtained for the study of photocatalytic hydrogen production, and the hydrogen production between graphene oxide and graphene was compared, and the mass fraction of graphene was adjusted. One of them is to use the reduced graphene, which accounts for 1% of the mass of TiO_2, to produce hydrogen. In summary, we use the TiO_2 nanocrystals, which have good properties, On the one hand, it is applied to polymer / nanocrystalline hybrid solar cells in aqueous phase as cathode interface modification layer to improve the conductivity and moisture resistance of the device, and optimize the device efficiency. On the other hand, the composite photocatalyst for hydrogen production is prepared by combining it with graphene, which has good conductivity, which can realize the utilization and conversion of solar energy and contribute a little to the future energy and sustainable development.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB383.1;TM914.4

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