基于原位微气泡成像的光催化水裂解产氢材料的高通量筛选研究

发布时间：2018-01-02 00:05

本文关键词：基于原位微气泡成像的光催化水裂解产氢材料的高通量筛选研究　出处：《陕西师范大学》2016年硕士论文　论文类型：学位论文

【摘要】：对化石燃料的过度开发与利用使人类目前面临着严重的环境污染与能源危机问题,因此,科学家们一直以来都在研究用清洁环保的可再生能源代替传统的不可再生的化石能源。研究者发现,半导体催化材料在太阳光的照射下,能够实现光催化分解水产生清洁的氢气,从而可以有效地解决环境污染和能源短缺问题。基于此发现,研究开发高效的半导体催化材料成为了提高光催化裂解水产氢效率的重要手段。单一的光催化剂由于其能带宽,量子效率低而很少应用在制氢技术中,相应的多组分光催化材料则表现出了很好的催化性能。但是光催化剂的种类很多,不同种类的不同配比的不同改性的催化材料组合起来形成的多组分催化材料更是不计其数,因此建立一种省时高效的筛选光催化剂的方法就显得尤为重要了。传统的催化剂筛选方法通常是“尝试—失败—再尝试”的模式,一次实验只能测试一种催化剂的性能,这无疑得消耗大量的时间和成本,而新近出现的高通量筛选方法因其具有微量、高效、灵敏、准确、可一次性检测大量样本的独特性能,从而解决了传统筛选方法难以克服的缺点。为此,本文将高通量筛选技术应用到制氢复合催化材料的筛选与性能评价中,建立了一种快速高效的筛选制氢催化材料的方法。获得的主要内容和结论如下：(1)以普通载玻片作为制备高通量反应芯片的片基,利用负性光刻胶的性质与光蚀刻技术的原理在片基上制备出了数量较多的500*500μm的疏水网格。该疏水网格作为高通量反应芯片上的微小反应单元相互之间具有独立性,可以满足高通量筛选技术对于芯片反应器的要求。(2)利用喷雾原理将纳米二氧化钛导入到反应芯片的各个微小反应单元内,作为复合催化剂材料的载体部分。然后基于彩色喷墨打印技术的原理,利用喷墨打印机将六种需要负载的金属离子按照设计好的不同配比打印在各个微小反应单元里,最后通过硫化,烧结等过程,制备出MSx/TiO_2催化剂库。通过XPS验证,制备的催化剂库与设计的相一致,满足实验要求,为后期的筛选实验打下了良好的基础。(3)利用CCD对微气泡的成像原理,建立一种基于微气泡成像技术的新的检测方法。由于原位微气泡成像的检测方法要求反应过程中产生的微小气泡不可发生移动,我们开发了一套适用于该检测方法的反应装置一准二维反应器。该反应器将反应空间的高度控制在0.5mm,使得形成狭小空间,保证反应产生的微小气泡不发生移动,满足了后续实验分析的要求。(4)通过对实验得到的气泡成像图片进行分析处理,以气泡大小作为催化活性高低的衡量标准,筛选出了催化活性最高的三种催化剂组配,其分别为：(Ni_(0.21)Zn_(0.22)Cd_(0.25)Y_(0.01)Co_(0.05)In_(0.26))SX/TiO_2, (Ni_(0.27)Zn_(0.21)Cd_(0.02)Y_(0.02)Co_(0.18)In_(0.30))SX/TiO_2, (Ni_(0.01)Zn_(0.27)Cd_(0.25)Y_(0.31)Co_(0.06)In_(0.10))SX/TiO_2。(5)将筛选出来的催化剂进行宏观性实验验证,结果表明,不同组配催化剂的宏观产氢效率与高通量筛选方法得到的理论催化活性是一致的。进一步证明了本研究设计的高通量筛选方法是科学的,可行的。
[Abstract]:The excessive exploitation and utilization of fossil fuels that humans are currently facing energy crisis and environmental pollution problems, so serious, scientists have been studying the use of renewable energy to replace the traditional non renewable fossil energy. The researchers found that the semiconductor catalytic materials under the irradiation of sunlight, can be realized the photocatalytic decomposition of water to produce clean hydrogen, which can effectively solve the problem of environmental pollution and energy shortage. Based on this discovery, the semiconductor catalytic materials research and development of high efficiency has become an important means to improve the photocatalytic efficiency of hydrogen cracking. Single photocatalyst because of its bandwidth, low quantum efficiency and little application in hydrogen production technology accordingly, the multi-component photocatalytic materials showed good catalytic performance. But the types of photocatalyst, different kinds of different proportions of different Modified multicomponent catalytic material of catalytic materials are combined to form the more is too many to count so the establishment of a screening method, highly efficient photocatalyst is particularly important. The traditional catalyst screening method is usually "try fail and try again" model, an experiment can only test performance of a catalyst this is undoubtedly, have consumed a lot of time and cost, and high throughput screening of the newly emerging method because of its high sensitivity, accuracy, trace, and unique properties of single detection of a large number of samples, so as to solve the traditional screening method is difficult to overcome the shortcomings. Therefore, this paper will be applied to high-throughput screening technology selection and performance evaluation of hydrogen catalytic composite material, a method was established for rapid and efficient screening of hydrogen production by catalytic materials. The main contents and conclusions are as follows: (1) to the common carrier as The preparation of high flux reaction chip base, using the principle of optical properties and etching technology of negative photoresist on the substrate of the prepared hydrophobic grid number more 500*500 m. The hydrophobic grid as micro reaction unit high-throughput reaction on a chip that is independent of each other, can meet the high throughput screening technology for the chip reactor requirements. (2) the principle using spray micro reaction unit of nanometer titanium dioxide into the reaction chip, as a carrier part of composite catalyst. Then the principle of color ink-jet printing technology based on the use of inkjet printer will be six kinds of metal ions to load in different ratio in each print design micro reaction unit, finally through vulcanization, sintering process, the preparation of MSx/TiO_2 catalyst library. Through XPS verification, preparation and design of base catalyst is consistent, To meet the experimental requirements, a good foundation for later screening experiments. (3) using CCD imaging principle of micro bubbles, to establish a new method for the detection of micro bubble based on imaging technology. Due to the tiny bubble detection imaging requirements in situ micro bubbles produced during the reaction can not move, reaction a two-dimensional reactor device we developed a set of suitable for the detection method. The reactor height control the reaction space in 0.5mm, so as to form a small space, that tiny bubbles generated in the reaction does not move, meet the subsequent experimental analysis. (4) by analyzing the bubble image of experiment the bubble size to the catalytic activity of the criterion, selected the highest catalytic activity of three kinds of catalysts with the group, respectively (Ni_ (0.21) Zn_ (0.22) Cd_ (0.25) Y_ (0.01) Co_ (0.05 In_) (0.26) (SX/TiO_2), Ni_ (0.27) Zn_ (0.21) Cd_ (0.02) Y_ (0.02) Co_ (0.18) In_ (0.30) (SX/TiO_2), Ni_ (0.01) Zn_ (0.27) Cd_ (0.25) Y_ (0.31) Co_ (0.06) In_ (0.10) (SX/TiO_2.) 5) the catalyst will be screened in the macroscopic experiments, the results show that the catalytic activity of the macro theory of hydrogen production efficiency and high throughput screening method with different groups of catalyst obtained is consistent. This study further proved that the design of high-throughput screening method is scientific and feasible.

【学位授予单位】：陕西师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TQ116.2

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