二氧化钛光阳极体系优化及太阳能光电化学分解水制氢应用
发布时间：2018-10-18 15:45
【摘要】：随着人们对太阳能-氢能这一转化过程关注的日益增加,光电化学(PEC)分解水制氢技术逐步在解决能源危机以及能源消耗方面取得了巨大进展。研究并拓展高效稳定光电极,使其具有可见光响应能力进而提高对太阳能利用率,这是优化PEC分解水制氢体系的先决条件。作为一类优异的光电极候选材料,二氧化钛(TiO_2)具有诸多优点,例如高光催化活性,持久稳定性,低成本和易合成等。同时,TiO_2也存在一些显著缺点,主要因为其仅能对紫外光响应(仅占太阳光的5%)并且光生电子-空穴对极易复合,所以单一TiO_2光电极的这些缺点已成为限制其工业应用的关键问题。目前已有多种方法被开发并用于提高TiO_2光电极的整体PEC效率,其中如何抑制PEC水分解制氢过程中的光生电子-空穴对复合是解决如上问题的主要思路。目前具体改进措施包括贵金属负载,缺陷引入,高分子材料复合和元素掺杂等。基于以上研究背景,本论文提出了如下三种TiO_2光电极优化方案并实现了高性能PEC新体系的构建:(1)首先我们通过多种合成方法制备了Au@CdS/RGO/TiO_2光电极,并通过SEM、TEM、Raman和XPS等表征证明了该独特异质结光电极已被成功制备。本工作首次将Au@CdS核-壳纳米粒子引入TiO_2光电极,以此赋予了TiO_2以可见光响应能力和等离体性能。此外,处于TiO_2和Au@CdS核-壳纳米颗粒中间的氧化还原石墨烯(RGO)薄膜在提高光生电荷传输速率方面发挥了重要作用。(2)通过原位光电还原法,我们在BiOCl纳米片表面成功修饰了等离子体Bi纳米颗粒(Bi/BiOCl),且将Bi/BiOCl作为光电阴极应用于TiO_2 Bi/BiOCl PEC太阳能水分解体系。同时,我们探讨了PEC性能与Bi/BiOCl复合比例之间的关系,并通过密度泛函理论证明了电荷是由Bi簇转移至BiOCl(001)面。根据IV曲线和电荷注入效率数据,我们进一步优化了Bi/BiOCl光电阴极。该体系中优异的PEC分解水效果主要归因于Bi纳米颗粒的电荷转移增强和表面等离子体共振(SPR)效应双重作用。(3)为了提高太阳光的利用和光电极的稳定性,我们使用有机聚合物多巴胺进一步敏化TiO_2光电极。在该体系中,我们将Bi-AgIn5S8负载于TiO_2光电极表面以实现其可见响应能力。在此基础上,进一步通过水热法制备了TiO_2/Bi-AgIn5S8/PDA异质结光电极。最后讨论了TiO_2/Bi-AgIn5S8/PDA异质结光电极的PEC分解水的机理,并分析了影响其PEC转换效率的因素。
[Abstract]:With the increasing attention to the conversion process of solar energy and hydrogen energy, photochemical (PEC) has gradually made great progress in resolving the energy crisis and energy consumption. It is a prerequisite to optimize the hydrogen production system of PEC decomposition water by studying and extending the high efficient and stable photoelectrode, which has the ability to respond to visible light and improve the utilization ratio of solar energy. As a kind of excellent optoelectronic candidate material, titanium dioxide (TiO_2) has many advantages, such as high photocatalytic activity, durable stability, low cost and easy synthesis. At the same time, TiO_2 also has some obvious disadvantages, mainly because it can only respond to ultraviolet light (only 5% of solar light) and photogenerated electron-hole pair is easy to recombine. So these disadvantages of single TiO_2 photoelectrode have become the key problem of limiting its industrial application. At present, many methods have been developed to improve the overall PEC efficiency of the TiO_2 photoelectrode, among which how to suppress the photogenerated electron-hole pair recombination in the process of the hydrogen production by the water decomposition of PEC is the main way to solve the above problem. At present, the specific improvement measures include noble metal loading, defect introduction, polymer composite and element doping. Based on the above research background, this paper proposes three kinds of TiO_2 optoelectronic pole optimization schemes and realizes the construction of a new high performance PEC system. (1) first, we have prepared the Au@CdS/RGO/TiO_2 photoelectrode by a variety of synthesis methods. The unique heterojunction photoelectrode has been successfully fabricated by SEM,TEM,Raman and XPS characterization. In this work, Au@CdS core-shell nanoparticles were introduced into the TiO_2 photoelectrode for the first time, thus giving TiO_2 the ability of visible light response and in vitro performance. In addition, redox graphene (RGO) films in the middle of TiO_2 and Au@CdS core-shell nanoparticles play an important role in increasing photocharge transfer rate. (2) in situ photoreduction, Plasma Bi nanoparticles (Bi/BiOCl) were successfully modified on the surface of BiOCl nanoparticles and Bi/BiOCl was used as photocathode in the TiO_2 Bi/BiOCl PEC solar water decomposition system. At the same time, we discuss the relationship between PEC performance and Bi/BiOCl composition ratio, and prove that the charge is transferred from Bi cluster to BiOCl (001) surface by density functional theory. Based on the IV curve and charge injection efficiency data, we further optimize the Bi/BiOCl photocathode. The excellent water decomposition effect of PEC in this system is mainly attributed to the double effects of the charge transfer enhancement of Bi nanoparticles and the (SPR) effect of surface plasmon resonance. (3) in order to improve the utilization of solar light and the stability of photoelectrode, We use organic polymer dopamine to further sensitize the TiO_2 photoelectrode. In this system, Bi-AgIn5S8 is loaded on the surface of TiO_2 photoelectrode to realize its visible response ability. On this basis, TiO_2/Bi-AgIn5S8/PDA heterojunction photoelectrodes were prepared by hydrothermal method. Finally, the mechanism of the PEC decomposition of the TiO_2/Bi-AgIn5S8/PDA heterojunction photoelectrode is discussed, and the factors affecting the PEC conversion efficiency are analyzed.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ116.2;O646.5
本文编号：2279596
[Abstract]:With the increasing attention to the conversion process of solar energy and hydrogen energy, photochemical (PEC) has gradually made great progress in resolving the energy crisis and energy consumption. It is a prerequisite to optimize the hydrogen production system of PEC decomposition water by studying and extending the high efficient and stable photoelectrode, which has the ability to respond to visible light and improve the utilization ratio of solar energy. As a kind of excellent optoelectronic candidate material, titanium dioxide (TiO_2) has many advantages, such as high photocatalytic activity, durable stability, low cost and easy synthesis. At the same time, TiO_2 also has some obvious disadvantages, mainly because it can only respond to ultraviolet light (only 5% of solar light) and photogenerated electron-hole pair is easy to recombine. So these disadvantages of single TiO_2 photoelectrode have become the key problem of limiting its industrial application. At present, many methods have been developed to improve the overall PEC efficiency of the TiO_2 photoelectrode, among which how to suppress the photogenerated electron-hole pair recombination in the process of the hydrogen production by the water decomposition of PEC is the main way to solve the above problem. At present, the specific improvement measures include noble metal loading, defect introduction, polymer composite and element doping. Based on the above research background, this paper proposes three kinds of TiO_2 optoelectronic pole optimization schemes and realizes the construction of a new high performance PEC system. (1) first, we have prepared the Au@CdS/RGO/TiO_2 photoelectrode by a variety of synthesis methods. The unique heterojunction photoelectrode has been successfully fabricated by SEM,TEM,Raman and XPS characterization. In this work, Au@CdS core-shell nanoparticles were introduced into the TiO_2 photoelectrode for the first time, thus giving TiO_2 the ability of visible light response and in vitro performance. In addition, redox graphene (RGO) films in the middle of TiO_2 and Au@CdS core-shell nanoparticles play an important role in increasing photocharge transfer rate. (2) in situ photoreduction, Plasma Bi nanoparticles (Bi/BiOCl) were successfully modified on the surface of BiOCl nanoparticles and Bi/BiOCl was used as photocathode in the TiO_2 Bi/BiOCl PEC solar water decomposition system. At the same time, we discuss the relationship between PEC performance and Bi/BiOCl composition ratio, and prove that the charge is transferred from Bi cluster to BiOCl (001) surface by density functional theory. Based on the IV curve and charge injection efficiency data, we further optimize the Bi/BiOCl photocathode. The excellent water decomposition effect of PEC in this system is mainly attributed to the double effects of the charge transfer enhancement of Bi nanoparticles and the (SPR) effect of surface plasmon resonance. (3) in order to improve the utilization of solar light and the stability of photoelectrode, We use organic polymer dopamine to further sensitize the TiO_2 photoelectrode. In this system, Bi-AgIn5S8 is loaded on the surface of TiO_2 photoelectrode to realize its visible response ability. On this basis, TiO_2/Bi-AgIn5S8/PDA heterojunction photoelectrodes were prepared by hydrothermal method. Finally, the mechanism of the PEC decomposition of the TiO_2/Bi-AgIn5S8/PDA heterojunction photoelectrode is discussed, and the factors affecting the PEC conversion efficiency are analyzed.
【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ116.2;O646.5
【参考文献】
相关期刊论文 前6条
1 Yong Na;Bo Hu;Qiu-Ling Yang;Jian Liu;Li Zhou;Rui-Qing Fan;Yu-Lin Yang;;CdS quantum dot sensitized p-type NiO as photocathode with integrated cobaloxime in photoelectrochemical cell for water splitting[J];Chinese Chemical Letters;2015年01期
2 金超;秦瑶;杨金虎;;新型非TiO_2半导体光催化剂[J];化学进展;2014年Z1期
3 徐守斌;江龙;杨海刚;宋远卿;淡宜;;光诱导聚合制备聚噻吩/二氧化钛复合粒子的结构及光催化性能[J];催化学报;2011年04期
4 徐军科;任克威;王晓蕾;周伟;潘相敏;马建新;;甲烷干重整制氢研究进展[J];天然气化工(C1化学与化工);2008年06期
5 雍永祜;;中国煤化工发展的思考[J];煤化工;2007年05期
6 李雪辉,王乐夫;环境友好催化技术发展趋势[J];化工进展;2001年06期
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