钴配合物催化产氢性能研究及光阴极器件组装

发布时间：2018-03-17 14:24

本文选题：钴配合物　切入点：三联吡啶钌　出处：《大连理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：太阳能是一种可再生的清洁能源,通过各种方式将太阳能应用于人类社会具有重要意义,其中利用太阳能光解水制氢是一种理想的利用途径。由于氢气具有很高的能量密度,被视为一种很有前景的化石燃料的替代品。在过去的十几年中,多组分催化和光电化学池被广泛研究,但产氢效率一直受到各种因素的限制。因此提高催化剂的光催化效率以及寻找高效的转化途径成为光解水催化产氢体系面临的巨大挑战。以此为背景,本论文以两种催化产氢体系为基础,开展了相应的研究工作：(1)以多吡啶钴为催化剂的均相催化体系的研究；(2)以钻肟分子催化剂与CdSe量子点的光阴极功能产氢器件的组装。以非贵金属钴与多吡啶结合的配合物为催化剂,[Ru(bPy)3]2+为光敏剂,抗坏血酸为电子牺牲体构建了均相催化体系,实现了纯水相催化质子还原产氢。通过催化体系的各种条件优化,经过11小时的光照实验,催化剂1 [Co(tpen)](BF4)2{tpen= N',N',N2,N2-tetrakis(pyridinyl-2-methy1)ethane-1,2-diamine}、2 [Co(bztpen)](BF4)2{bztpen= N'-benzyl-N1,N2,N2-tris(pyridinyl-2-methyl)ethane-1,2-diamine}、3 [Co(dbzbpen)](BF4)2{ dbzbpen= N',N2-dibenzyl-N1,N2-bis(pyridinyl-2-methyl)ethane-1,2-diamine}的TON值分别达到639、2078、98,催化剂1和2的光量子效率分别达到0.48%和1.51%。经过长时间的光照,催化体系出现明显的失活现象,研究发现,催化剂和光敏剂作为金属有机配合物,均出现了明显的分解而使体系失活。同时根据电化学实验结果和相应的文献,我们推测了该体系催化反应产氢机理,三联毗啶钌光敏剂激发态的淬灭途径为还原淬灭。将钴肟分子催化剂和巯基乙酸修饰的CdSe量子点光敏剂,通过化学键合的方式吸附到多孔p型NiO的表面,组成光阴极器件,能够实现光驱动催化质子还原产氢。其中CdSe量子点通过SILAR (successive ionic layer adsorption and reaction)法和OIAR(one-pot in situ adsorption and reaction)法两种方式敏化到NiO表面,而使用多孔NiO大大增加了电极的比表面积,提高了光敏剂和催化剂的吸附量。以3 W的LED蓝光灯作为光源,在相对标准氢为0 V的电压下、0.1 M pH 7的中性Na2SO4水溶液中,无论是采用SILAR法还是OIAR法制备的组装器件的光电流密度都能够达到100 μA cm-2以上,效率比文献报道的基于NiO的光阴极提高了4-5倍。在稳定性测试中,我们以OIAR法制备的器件为例,进行了长时间的光照实验,经过1.5 h的光电解水实验,光电流密度仅下降了6%左右,表明所制备的光阴极器件具有较好的稳定性。
[Abstract]:Solar energy is a kind of renewable and clean energy. It is of great significance to apply solar energy to human society in various ways. Among them, photodissociation of solar energy to produce hydrogen is an ideal way, because hydrogen has a high energy density. As a promising alternative to fossil fuels, multicomponent catalysis and photoelectrochemical cells have been extensively studied in the past decade. However, the efficiency of hydrogen production has always been limited by various factors. Therefore, improving the photocatalytic efficiency of catalysts and finding efficient conversion pathways are the great challenges faced by hydrolysate catalytic hydrogen production system. This thesis is based on two catalytic hydrogen production systems. A study on the homogeneous catalytic system using cobalt polypyridine as catalyst was carried out. The assembly of photocathode functional hydrogen production devices using drilloxime molecular catalyst and CdSe quantum dots was carried out. Non-noble metal cobalt and polypyridine were used to combine with polypyridine. [Ru(bPy)3] 2 was used as Guang Min, The homogeneous catalytic system of ascorbic acid for electron sacrificial was constructed, and the pure water phase catalyst for proton and hydrogen production was realized. Through the optimization of various conditions of the catalytic system, after 11 hours of light experiment, Catalyst 1 [Cotpene] BF4N 2 {tpen2 = N2 Ntpenn 2 tetrakispyridinyl-2-methy1ethane-1ane-2-diamine} 2 [Cobztpen2] BF4tpen2 {bztpen2 = N- benzyl-N2N2N2trispyridinyl-2-methylethane-12-diamine} 3 [Codbzbpenyl] BF42 {dbzbpenyl = NNN2-dibenzyl-NN2-bispyridinyl-2-methylethanethan1e-diamine} the TON values of the catalyst reached 92079891, and the photocatalytic efficiency of the catalyst reached 0.48%, respectively. The catalyst and Guang Min were used as metal-organic complexes, which resulted in obvious decomposition and deactivation of the system. Based on the results of electrochemical experiments and the corresponding literature, we speculated the mechanism of hydrogen production in the catalytic reaction of the system. Reduction quenching is the way to quench the excited state of tripyridine ruthenium Guang Min. The cobalt oxime molecular catalyst and CdSe quantum dot Guang Min modified with thioglycolic acid are chemically bonded onto the surface of porous p-type NiO to form photocathode devices. CdSe quantum dots are sensitized to the NiO surface by means of SILAR succeeded ionic layer adsorption and reactionation method and OIAR(one-pot in situ adsorption and reactionation method, and the specific surface area of the electrode is greatly increased by using porous NiO. The adsorption capacity of Guang Min and catalyst was increased by using a 3W LED blue light lamp as a light source in a neutral Na2SO4 aqueous solution of 0.1 M pH 7 at a voltage of 0 V relative to standard hydrogen. The photocurrent density of the assembled devices prepared by either SILAR method or OIAR method can reach more than 100 渭 A cm-2, and the efficiency is 4-5 times higher than that of the photocathode based on NiO reported in the literature. In the stability test, we take the device fabricated by OIAR method as an example. The photocurrent density has been reduced by only about 6% after 1.5 h photoelectrolysis experiment, which shows that the photocathode device has good stability.
【学位授予单位】：大连理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ116.2

【共引文献】