新型光催化电极材料的合成及其光电催化性能的探究

发布时间：2018-04-04 03:36

  本文选题：异相结　切入点：光解水制氢　出处：《上海师范大学》2017年硕士论文

【摘要】：能源危机以及环境污染问题一直是制约当前人类社会发展的两个重大问题,使用清洁能源代替化石能源,构筑可再生资源,代替化石能源,是解决上述问题的有效途径之一。太阳能作为一种取之不尽、用之不竭的清洁能源,能很好的为人类社会提供能源动力,但是太阳能利用率低、使用成本高,间歇性的能源供应等问题限制了太阳能的广泛应用。而光电催化技术,能够有效地将太阳能储存于化学物质之中,应用于工业生产,其中,氢能被学者广泛地认为是一种无污染、储能高的新能源,是21世纪最有潜力的替代能源。所以光电催化制备氢气获得了广泛地研究。半导体光催化技术可直接利用太阳能分解水制备氢气,而其中TiO_2作为典型半导体,获得了广泛的研究。但是光吸收范围窄,光生电子和空穴复合速率高等问题限制了其实际的应用。为了解决这些问题,我们目前采用的手段有金属修饰,半导体复合,异相结等光催化掺杂技术,结合电化学技术,实现光电催化性能提升的效果。在本文中,我们主要的研究内容如下:(1)结合锐钛矿相的TiO_2和金红石相的TiO_2,其禁带宽度,导带和价带的不同,运用水热、醇热的制备方法,在金红石相的TiO_2纳米棒阵列FTO电极上,负载小颗粒的锐钛矿相TiO_2纳米点,构筑异相结电极材料,系统地研究了材料在紫外光下,分解水产生氢气的光电催化性能。通过该电极作为光阳极,一定程度地提高了光电转化产氢的效率。(2)运用简单的一步水热的办法,在铜泡沫的基底上,构筑金红石相的TiO_2纳米棒,通过TiCl3作为前驱液,以金属铜作为良好的导电子材料,提供了一种有效促使电子空穴分离的路径。另一方面,铜泡沫所形成的的多孔多基底面积,为阳极的反应提供了有效的接触面,可以很大程度提高光催化产氢的速率,铜泡沫宏观的多空结构,利于单位面积光的反复照射和利用,避免了单位平面的堆垛催化剂,增大了纳米尺寸。(3)运用简单的浸渍、水热的方法,将铜泡沫形成Cu_2O阵列,并在之后,进行TiO_2纳米薄片的包裹,形成Branched形貌,这一方面保护了Cu_2O阵列,另一方面,也是P型Cu_2O电子传导的重要途径。我们将该电极作光阴极,该电极具有良好的CO_2还原选择性,能够高效地将CO_2还原为甲酸。(4)通过浸渍的方法,将C_(60)分散到甲苯溶液中,并与g-C_3N_4的前驱物三聚氰胺进行均匀混合,并在之后形成C_(60)分散的g-C_3N_4,C_(60)作为一种良好的电子传导剂,能够很好地将电子从C_3N_4上传输到C_(60)上,从而有效地拉动了电子,增强g-C_3N_4光催化性能。
[Abstract]:Energy crisis and environmental pollution are two major problems restricting the development of human society. The use of clean energy instead of fossil energy, the construction of renewable resources and the replacement of fossil energy is one of the effective ways to solve these problems.Solar energy, as an inexhaustible clean energy, can provide energy power for human society, but the low utilization rate of solar energy, high cost of use, intermittent energy supply and other problems limit the wide application of solar energy.Photocatalytic technology can effectively store solar energy in chemical materials and be used in industrial production. Among them, hydrogen energy is widely regarded by scholars as a new energy source with no pollution and high energy storage, which is the most potential alternative energy in the 21st century.Therefore, photocatalytic preparation of hydrogen has been widely studied.Semiconductor photocatalytic technology can directly use solar energy to decompose water to produce hydrogen, and TiO_2, as a typical semiconductor, has been widely studied.However, its practical application is limited by the narrow optical absorption range and high recombination rate of photogenerated electrons and holes.In order to solve these problems, we have adopted the methods of metal modification, semiconductor recombination, heterogeneous junction and other photocatalytic doping technology, combined with electrochemical technology, to achieve the effect of improving the photocatalytic performance.In this paper, the main contents of our research are as follows: (1) in combination with anatase phase TiO_2 and rutile phase TiO2, the band gap, conduction band and valence band are different, using hydrothermal and alcohol heat preparation methods, on the TiO_2 nanorod array FTO electrode of rutile phase.The photocatalytic properties of anatase phase TiO_2 nanowires loaded with small particles to produce hydrogen by decomposing water under ultraviolet light have been systematically studied by constructing heterogeneous junction electrode materials.By using the electrode as a photoanode, the efficiency of photoconversion for hydrogen production has been improved to a certain extent. A simple one-step hydrothermal method has been used to construct rutile TiO_2 nanorods on the copper foam substrate and TiCl3 as the precursor solution.Metal copper as a good electron conducting material provides an effective path to the separation of electron holes.On the other hand, the porous multi-substrate area formed by the copper foam provides an effective contact surface for the anodic reaction, which can greatly increase the rate of photocatalytic hydrogen production, and the macroporous structure of the copper foam.It is advantageous to the repeated irradiation and utilization of light per unit area, avoids the stacking catalyst in unit plane, and increases the nanometer size. (3) the copper foam is formed into Cu_2O array by simple impregnation, hydrothermal method, and then,The Branched morphology is formed by encapsulating the TiO_2 nanocrystals, which protects the Cu_2O array on the one hand, and on the other hand, it is also an important way of conducting P-type Cu_2O electrons.We used the electrode as a photocathode. The electrode has good CO_2 reduction selectivity, and can efficiently reduce CO_2 to formic acid. 4) by impregnation, Che 60) is dispersed into toluene solution and mixed evenly with melamine, the precursor of g-C_3N_4.As a good electron conduction agent, it can transport electrons from C_3N_4 to CSC60), thus effectively pulling electrons and enhancing the photocatalytic performance of g-C_3N_4.
【学位授予单位】：上海师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36
，

本文编号：1708193