基于分子催化剂的染料敏化光阳极的性能研究
发布时间：2018-12-26 06:40
【摘要】：随着能源和环境等全球性问题的日益突出,可再生能源对于解决这些问题起到了至关重要的作用。由于太阳能取之不尽用之不竭,将其转化为环保的、友好的可再生能源已备受世界各国科学家们的关注。利用人工光合作用构建光电化学电池,模拟自然界中的绿色植物的光合作用原理,实现把太阳能转化为稳定、易储存的化学能[1-7],这种科技的研究正走在科学领域的前沿,但由于光合作用的复杂性和对外界条件要求较高,氧化水是将水解离出4个电子和4个质子的过程,这个半反应也是持续发展人工光合作用的瓶颈。因此研究经济、高效、稳定的水氧化催化剂是解决上述问题的突破口。本文制备了高效廉价的且合成简单的水氧化催化剂Co_4O_4(O2CMe)4(4-vinylpy)4(Co_4O_4),模仿了PSII的释氧复合物(OEC)的立方结构,以TiO_2为基底的钌配合物作为光敏剂,通过共价键吸附和电聚合双重方法将钴立方烷分子催化剂修饰到钌配合物染料敏化的光阳极上,其光电性能测试实验证明,以pH 7.0的0.10 mol/L硫酸钠溶液为电解质,染料敏化修饰光阳极光电流密度能够达到100μA/cm2且稳定性好,法拉第效率达到76%。同位素效应的测试中也表明染料敏化修饰光阳极在光解水的过程中,光敏剂与催化剂之间的电子转移为整个光解水过程中的速率控制步骤。此外,本文还合成了高效钌配合物催化剂,同样运用共价键吸附和电聚合双重方法组成分子型染料敏化光解水分子器件,其光电流密度明显提升。由于TiO_2基底在整个修饰光阳极中也具有影响,研究发现在涂有TiO_2浆料的基底上再通过TiCl4水解修饰上TiO_2的光阳极效果更好,更有利于光敏剂和催化剂的吸附。并选择了最优光强100 mW/cm2,同样选择在pH 7.0,0.10 mol/L的Na2SO4溶液为电解质,在这样的条件下,分子型染料敏化光解水分子器件的光电流密度比钴立方烷催化剂修饰光阳极提升6倍以上,达600μA/cm2且稳定,基于两种不同的水氧化催化剂运用相同的修饰方法来组装染料敏化光阳极对研究分子型光阳极的发展具有启发作用。
[Abstract]:With the increasingly prominent global problems such as energy and environment, renewable energy plays a vital role in solving these problems. As solar energy is inexhaustible, it has attracted the attention of scientists all over the world. Using artificial photosynthesis to construct photovoltaic cells, simulate the principle of photosynthesis of green plants in nature, and realize the conversion of solar energy into stable and easily stored chemical energy [1-7]. The research of this kind of technology is at the forefront of the scientific field, but because of the complexity of photosynthesis and the high demand for external conditions, oxidized water is the process of dissociating water from four electrons and four protons. This half-reaction is also the bottleneck of sustainable development of artificial photosynthesis. Therefore, the research of economic, efficient and stable water oxidation catalyst is the breakthrough to solve the above problems. In this paper, a simple water oxidation catalyst Co_4O_4 (O2CMe) 4 (4-vinylpy) 4 (Co_4O_4) was prepared, which mimics the cubic structure of PSII's oxygen-releasing complex (OEC). Ruthenium complex based on TiO_2 was used as Guang Min. Cobalt cubic alkane molecular catalyst was modified on the photoanode sensitized by ruthenium complex by covalent bond adsorption and electropolymerization. The photoelectric properties of the catalyst were tested. Using 0.10 mol/L sodium sulfate solution of pH 7.0 as electrolyte, the dye sensitized modified photo-positive auroral current density can reach 100 渭 A/cm2 and the stability is good. Faraday efficiency is 76%. The isotopic effect also shows that the electron transfer between Guang Min and catalyst is the rate control step in the whole process of photodegradation of water. In addition, the highly efficient ruthenium complex catalyst was synthesized, and the photocurrent density of the molecular dye sensitized photodissociation molecular device was also increased by using covalent bond adsorption and electropolymerization. As the TiO_2 substrate also has an effect on the whole modified photoanode, it is found that the photoanode effect of TiO_2 on the substrate coated with TiO_2 slurry is better than that on the substrate coated with TiCl4 hydrolysis, which is more favorable for the adsorption of Guang Min and catalyst. The optimal light intensity of 100 mW/cm2, was also selected as the electrolyte in the Na2SO4 solution of pH 7.0 mol/L 0.10 mol/L. The photocurrent density of the molecular dye sensitized photodissociation molecular device is more than 6 times higher than that of the cobalt cubic alkane catalyst modified photoanode, reaching 600 渭 A/cm2 and stable. Using the same modification method to assemble dye sensitized photoanode based on two different kinds of water oxidation catalysts has enlightening effect on the development of molecular photoanode.
【学位授予单位】：辽宁大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36
[Abstract]:With the increasingly prominent global problems such as energy and environment, renewable energy plays a vital role in solving these problems. As solar energy is inexhaustible, it has attracted the attention of scientists all over the world. Using artificial photosynthesis to construct photovoltaic cells, simulate the principle of photosynthesis of green plants in nature, and realize the conversion of solar energy into stable and easily stored chemical energy [1-7]. The research of this kind of technology is at the forefront of the scientific field, but because of the complexity of photosynthesis and the high demand for external conditions, oxidized water is the process of dissociating water from four electrons and four protons. This half-reaction is also the bottleneck of sustainable development of artificial photosynthesis. Therefore, the research of economic, efficient and stable water oxidation catalyst is the breakthrough to solve the above problems. In this paper, a simple water oxidation catalyst Co_4O_4 (O2CMe) 4 (4-vinylpy) 4 (Co_4O_4) was prepared, which mimics the cubic structure of PSII's oxygen-releasing complex (OEC). Ruthenium complex based on TiO_2 was used as Guang Min. Cobalt cubic alkane molecular catalyst was modified on the photoanode sensitized by ruthenium complex by covalent bond adsorption and electropolymerization. The photoelectric properties of the catalyst were tested. Using 0.10 mol/L sodium sulfate solution of pH 7.0 as electrolyte, the dye sensitized modified photo-positive auroral current density can reach 100 渭 A/cm2 and the stability is good. Faraday efficiency is 76%. The isotopic effect also shows that the electron transfer between Guang Min and catalyst is the rate control step in the whole process of photodegradation of water. In addition, the highly efficient ruthenium complex catalyst was synthesized, and the photocurrent density of the molecular dye sensitized photodissociation molecular device was also increased by using covalent bond adsorption and electropolymerization. As the TiO_2 substrate also has an effect on the whole modified photoanode, it is found that the photoanode effect of TiO_2 on the substrate coated with TiO_2 slurry is better than that on the substrate coated with TiCl4 hydrolysis, which is more favorable for the adsorption of Guang Min and catalyst. The optimal light intensity of 100 mW/cm2, was also selected as the electrolyte in the Na2SO4 solution of pH 7.0 mol/L 0.10 mol/L. The photocurrent density of the molecular dye sensitized photodissociation molecular device is more than 6 times higher than that of the cobalt cubic alkane catalyst modified photoanode, reaching 600 渭 A/cm2 and stable. Using the same modification method to assemble dye sensitized photoanode based on two different kinds of water oxidation catalysts has enlightening effect on the development of molecular photoanode.
【学位授予单位】：辽宁大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36
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