钨系多酸盐修饰DSSC光电极的制备及光电性能研究

发布时间：2018-06-18 08:33

本文选题：染料敏化太阳能电池 + 光阳极改性　；参考：《哈尔滨工业大学》2017年博士论文

【摘要】：染料敏化太阳能电池(DSSC)自1991年诞生以来,得到了长足的发展,但是也存在一定的问题。TiO2基的DSSC光阳极只能吸收波长小于387 nm的紫外光,使得电池的吸收光谱与太阳光光谱不匹配,TiO2较宽的带隙降低了光生电子的注入效率,在光阳极界面间的载流子的复合作用,限制了电池光电流密度的提升。钌基N719染料在可见光区的吸收较弱,影响了电池光电转换性能的进一步提高。传统的Pt对电极不但储量有限价格昂贵,电池的高生产成本,限制了染料敏化太阳能电池的发展。因此,制备新型的光阳极复合材料、提高对电极的催化性能及稳定性显得尤为重要。本论文针对上述DSSC存在的问题,将结构和性能优异的多金属氧酸盐材料引入到染料敏化太阳能电池的电极中,合成了三种多金属氧酸盐化合物,并对它们进行了光电化学性质研究。从能级匹配、提高电池对太阳光谱的响应范围、改善电池对电极的催化作用角度考察了其应用于传统TiO2基染料敏化太阳能电池体系中的可能性;从能级结构、电子寿命、电池稳定性等方面研究了改性后电池效率提高的原因。研究结果表明,多金属氧酸盐修饰的TiO2光阳极将电池的光吸收范围拓展到了可见光区,起到了光谱补偿和光谱增效的双重作用,降低了TiO2的禁带宽度,提高了电子由N719染料注入到TiO2导带的效率,抑制了电池内部载流子的反向复合作用,使得电子寿命得以延长;多金属氧酸盐复合的对电极,增强了其催化活性,进一步提高了电池的光电转化性能。采用溶剂热的方法制备了SiW11Ni和SiW11Cu两种多金属氧酸盐,通过紫外可见近红外以及光谱电化学的测试手段分析了它们应用到DSSC中的可能性,通过电流-电压曲线,表面光电压、电化学阻抗,开路电压衰减、单色光效率谱等方法研究了多金属氧酸盐在TiO2基DSSC光阳极中的作用机理。实验结果表明,这两种多金属氧酸盐改性后的光阳极,其禁带宽度变窄,进而提高了激发态电子注入到光阳极导带的驱动力,扩宽了器件对太阳光的吸收范围,提高了电池的光电流密度;同时,提高了电池中光生电子与空穴的分离能力,促进了电子传输、延长了电子寿命。多酸盐改性后的TiO2光阳极电池其光电转换效率比空白电池提高了22%,短路电流密度提升了31%。将多酸盐SiW11Ni引入到染料敏化太阳电池的光阴极中,制备了SiW11Ni复合的Pt对电极,减少了贵金属Pt的用量。采用循环伏安、塔菲尔极化曲线和电化学阻抗的测试方法研究了复合对电极SiW11Ni/Pt的催化性质,同时也研究了电池的稳定性。实验结果表明:SiW11Ni复合的Pt对电极具有较高的催化活性,促进了对电极电解液中I-/I3-的循环速度,加快染料再生的速度,与传统的Pt对电极电池相比,电池的光电转换性能提高了16%,短路电流密度提升了34%。在多金属氧酸盐修饰光阳极和对电极的基础上,我们将SiW11Cu多酸盐同时引入到DSSC的两个光电极上,优化了电池结构,组装DSSC并测试了电池性能。结果表明,SiW11Cu多酸盐在DSSC中起到了双重作用,降低了电池的生产成本(以克为单位计算,其生产成本约为Pt的1/50),提高了对电极对电解液的催化作用,采用SiW11Cu复合的Pt对电极电池的光电性能提升了16%,短路电流密度提升了34%。针对多酸盐较好的吸光性能,在水热合成的条件下,选择合成了吸光性能更好、能级匹配的Na3.5Co4[Bi2Co2W19.75O70(H2O)6]·39.5H2O(BiWCo)多酸盐,进一步提升了电池在可见光区的吸收范围,将光吸收范围扩展至约800 nm,BiWCo多酸盐可以起到敏化剂的作用,提高电子注入TiO2中的数量,抑制电子的复合,提高电子的注入效率。与空白电池相比,以BiWCo/TiO2作为光阳极电池的光电转化效率由6.38%提高到了8.16%,短路电流密度提高了32%。
[Abstract]:Dye-sensitized solar cell (DSSC) has been greatly developed since its birth in 1991. However, there are some problems with the.TiO2 based DSSC photoanode that only absorbs ultraviolet light less than 387 nm, which makes the absorption spectrum of the battery do not match the solar light spectrum. The wide band gap of TiO2 reduces the injection efficiency of the photoelectron, in Guangyang The recombination between the carriers in the polar interface limits the increase of the photocurrent density of the battery. The weak absorption of the ruthenium based N719 dye in the visible light area affects the further improvement of the photoelectric conversion performance of the battery. The traditional Pt has limited reserves and high cost, and the high production cost of the battery limits the hair of the dye sensitized solar cells. Therefore, it is very important to prepare a new type of photo anode composite to improve the catalytic performance and stability of the electrode. In this paper, three kinds of polyoxometalate compounds are synthesized by introducing the polyoxometalate material with excellent structure and performance into the electrode of the dye sensitized solar cell for the problems of the DSSC. They have studied the photoelectric chemical properties. From the energy level matching, the increase of the response range of the solar spectrum to the solar spectrum and the improvement of the catalytic action of the battery to the electrode, the possibility of its application in the traditional TiO2 based dye sensitized solar cell system is investigated. The modified electric power is studied from the energy level structure, the electronic life life, the battery stability and so on. The research results show that the TiO2 photo anode modified by polyoxometalate extends the light absorption range of the battery to the visible light area, which plays the dual role of spectral compensation and spectral synergy, reduces the band gap of TiO2, improves the efficiency of the electron from N719 dye into the conduction band of the TiO2, and inhibits the internal load of the battery. The reverse recombination of the flow subsides makes the electronic life longer, and the polyoxometalate compound pair electrode enhances its catalytic activity and further improves the photoelectric conversion performance of the battery. Two kinds of SiW11Ni and SiW11Cu polyoxometalate are prepared by the solvent heat method, and the ultraviolet visible near infrared and spectroelectrochemistry are tested through the ultraviolet light. The possibility of their application to DSSC was analyzed by means of the method. The action mechanism of Polyoxometalates in the TiO2 based DSSC photoanode was studied through the current voltage curve, the surface photovoltage, the electrochemical impedance, the open circuit voltage attenuation, and the monochromatic light efficiency spectrum. The experimental results showed that the two kinds of polyoxometalates modified by the photoanode were forbidden. With the narrowing of the width, the driving force of the excited state electron injection into the photoanode guide band is enhanced, the absorption range of the solar light is widened and the photocurrent density of the battery is increased. At the same time, the separation ability of the photoelectron and hole in the battery is improved, the electron transport is promoted and the electronic life is extended. The TiO2 Guangyang after the polyacid salt modification is extended. The photoelectric conversion efficiency of the polar battery is 22% higher than that of the blank battery, the short circuit current density increases 31%. and the polyacid SiW11Ni is introduced into the photocathode of the dye-sensitized solar cell. The SiW11Ni composite Pt pair electrode is prepared, and the amount of the precious metal Pt is reduced. The measurement method of the cyclic voltammetry, Tafel polarization curve and electrochemical impedance is used. The catalytic properties of the composite electrode SiW11Ni/Pt are studied and the stability of the battery is also studied. The experimental results show that the SiW11Ni compound Pt has high catalytic activity to the electrode, promotes the circulation speed of I-/I3- in the electrode electrolyte, speeds up the speed of the dye regeneration, and compares the photoelectric conversion of the battery with the traditional Pt electrode battery. The performance increased by 16%, the short circuit current density increased 34%. on the basis of the polyoxometalate modified photoanode and the pair electrode. We introduced the SiW11Cu polyacid to the two optoelectronic poles of DSSC, optimized the battery structure, assembled the DSSC and tested the battery performance. The results showed that the SiW11Cu polyacid played a dual role in DSSC and decreased. The production cost of the battery is lower (the cost of the production cost is about Pt 1/50), which improves the catalytic activity of the electrode to the electrolyte. The SiW11Cu composite Pt has improved the photoelectric performance of the electrode battery by 16%. The short circuit current density improves the better absorbability of 34%. against the polyacid, and is selected under the condition of hydrothermal synthesis. Na3.5Co4[Bi2Co2W19.75O70 (H2O) 6] / 39.5H2O (BiWCo) polyacid is synthesized with better absorbability and energy level, which further improves the absorption range of the battery in the visible light area, extending the light absorption range to about 800 nm. BiWCo polyacid can play the role of sensitizer, increase the number of electron injected TiO2, inhibit the recombination of electrons, and lift the recombination of electrons. The efficiency of high electron injection. Compared with the blank battery, the photoelectric conversion efficiency of the BiWCo/TiO2 as an anodic battery increased from 6.38% to 8.16%, and the short circuit current density increased by 32%.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：O646;TM914.4

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