基于硅纳米线阵列的光催化体系的构建及其光催化还原水制氢性能

发布时间：2018-05-14 03:00

本文选题：Si纳米线阵列 + EDTA金属配合物　；参考：《上海应用技术学院》2015年硕士论文

【摘要】：硅纳米线以其独特的光电性能受到了越来越多的研究者的关注。随着研究的深入,使用硅纳米线(SiNWs)阵列作为光催化剂来制备氢气也引起了人们的广泛兴趣,成为了目前光催化制氢领域的新热点。为此,我们在本论文的研究中,利用乙二胺四乙酸金属配合物(EDTA-M, M=Ni、Co)同时作为光敏化剂和牺牲剂,设计并构建了一系列基于SiNWs阵列的光催化体系,并在模拟太阳光的照射下,考察了上述催化体系的光催化还原水制氢性能。具体研究内容如下：(1)在模拟太阳光的条件下,使用EDTA-Ni作为光敏化剂和牺牲剂,构建了EDTA-Ni敏化的SiNWs阵列,并考察了其光催化还原水制氢性能。此外,还通过光电化学手段对该催化体系的光催化还原水制氢机理进行了初步探讨。研究结果表明：EDTA-Ni敏化的SiNWs阵列是一个性能较为优异的光催化制氢催化剂,其光催化制氢速率可达2.41 L.m2.h-1。在光催化还原水制氢过程中,EDTA-Ni既是敏化剂又是牺牲剂,起着非常重要的作用,可以显著地提高SiNWs阵列对可见光的利用效率。当使用EDTA-Ni替代EDTA-Na时, SiNWs阵列对λ500 nm光的利用效率提高了5倍。另外,实验结果还表明EDTA-Ni敏化的SiNWs阵列具有良好的光稳定性和可循环性能。(2)在上述研究的基础上,使用EDTA-Ni/EDTA-Co混合配合物代替单一EDTA-Ni作为敏化剂和牺牲剂,构建了EDTA-Ni/EDTA-Co共敏化的SiNWs阵列,并在模拟太阳光的条件下,考察了其光催化还原水制氢性能。研究结果表明：利用EDTA-Ni/EDTA-Co的协同作用,可以进一步提高SiNWs阵列的光催化制氢效率,其光催化制氢速率可达2.8 L.m2.h-1。此外,光电化学手段还表明,在光催化还原水制氢过程中,EDTA-Ni与EDTA-Co之间存在着明显的协同作用。这导致SiNWs阵列工作波长被进一步拓宽。(3)通过在SiNWs阵列上接枝Ti02纳米棒,构建了TiO2-Si纳米“森林”。随后,使用EDTA-Ni作为光敏化剂和牺牲剂,考察了该纳米“森林”的光催化还原水制氢性能,并通过光电化学手段对其光催化还原水制氢机理进行了初步探讨。研究结果表明：通过构筑TiO2-Si纳米“森林”复合光催化体系,纳米Ti02的光催化还原水制氢性能得到了明显改善。相比于在SiNWs阵列上简单涂覆的P25, TiO2-Si纳米“森林”的光催化制氢速率是其近2倍。这意味着在固体基片上构建TiO2-Si纳米“森林”是一个很好的、Ti02纳米材料的固定手段。可有效解决Ti02纳米粒子固定化所带来的光催化效率下降的问题。
[Abstract]:Silicon nanowires have attracted more and more attention due to their unique photoelectric properties. With the development of research, the use of silicon nanowires (SiNWs) arrays as photocatalysts to produce hydrogen has attracted extensive interest and become a new hot spot in the field of photocatalytic hydrogen production. Therefore, in this thesis, a series of photocatalytic systems based on SiNWs arrays were designed and constructed by using EDTA-MMNICO as Guang Min agents and sacrificial agents, and under simulated solar irradiation, a series of photocatalytic systems based on SiNWs arrays were designed and constructed. The photocatalytic reduction of water for hydrogen production was investigated. The main contents of this study are as follows: (1) under the condition of simulated solar light, EDTA-Ni sensitized SiNWs array was constructed by using EDTA-Ni as Guang Min agent and sacrificial agent, and its photocatalytic reduction of water for hydrogen production was investigated. In addition, the mechanism of photocatalytic reduction of water for hydrogen production was also discussed by photochemical method. The results show that the SiNWs array sensitized by 1: EDTA-Ni is an excellent photocatalytic catalyst for hydrogen production, and the photocatalytic hydrogen production rate can reach 2.41 L 路m ~ (2. 2) h ~ (-1). In the process of photocatalytic reduction of hydrogen from water, EDTA-Ni is both a sensitizer and a sacrificial agent, which plays a very important role in improving the efficiency of visible light utilization of SiNWs arrays. When EDTA-Na was replaced by EDTA-Ni, the utilization efficiency of 位 500nm light in SiNWs array was increased by 5 times. In addition, the experimental results also show that the SiNWs array sensitized by EDTA-Ni has good photostability and reproducibility. (2) on the basis of the above research, the mixed EDTA-Ni/EDTA-Co complex is used instead of a single EDTA-Ni as sensitizer and sacrificial agent. A EDTA-Ni/EDTA-Co co-sensitized SiNWs array was constructed and its photocatalytic reduction of water for hydrogen production was investigated under simulated solar light. The results show that the photocatalytic hydrogen production efficiency of SiNWs arrays can be further improved by using the synergistic effect of EDTA-Ni/EDTA-Co, and the photocatalytic hydrogen production rate can reach 2.8 L 路m ~ (2. 2) h ~ (-1). In addition, the photochemical method also shows that there is an obvious synergism between EDTA-Ni and EDTA-Co in the process of photocatalytic reduction of hydrogen from water. As a result, the working wavelengths of SiNWs arrays were further broadened. (3) by grafting Ti02 nanorods onto SiNWs arrays, the "forest" of TiO2-Si nanocrystals was constructed. Then, EDTA-Ni was used as Guang Min agent and sacrificial agent to investigate the photocatalytic reduction of water for hydrogen production. The mechanism of photocatalytic reduction of water for hydrogen production was preliminarily discussed by photochemical means. The results show that the photocatalytic reduction of water for hydrogen production by TiO2-Si nanocrystalline "forest" composite photocatalytic system has been improved obviously. Compared with P25 coated on SiNWs arrays, the photocatalytic hydrogen production rate of TiO2-Si nano-" forest "is nearly twice as high as that of P25. This means that the construction of TiO2-Si nanoscale "forest" on solid substrates is a good immobilization method for Ti02 nanomaterials. It can effectively solve the problem of decreasing photocatalytic efficiency caused by immobilization of Ti02 nanoparticles.
【学位授予单位】：上海应用技术学院
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：O643.36;TQ116.2

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