基于二维材料的纳米杂化体系构筑与相关电化学性质研究

发布时间：2018-05-06 19:17

本文选题：二维材料 + 石墨烯　；参考：《清华大学》2015年博士论文

【摘要】：以石墨烯为代表的二维材料经过十年的研究已经取得了全面进展,同时二维材料概念也渗透到各个领域。目前,以二维材料为基本单元来设计和构筑纳米杂化体系是领域内重要的研究方向。发展基于二维材料的纳米杂化体系,一方面可以对二维材料自身物理和化学性质有更深入的认识,另一方面可拓展二维材料和与之复合的功能材料之应用范围。本论文针对能源与环境领域一些重要电化学过程所需材料,发展新合成方法构筑基于二维材料的新型纳米杂化体系,并充分结合二维材料特性来提高杂化体系电化学性能,具体如下:一、相对于大尺寸金纳米粒子,直径小于2纳米的金纳米团簇具有较高氧气催化还原(ORR)活性。但金纳米团簇的实际应用面临一些问题,例如合成后表面残留包覆剂降低了ORR活性,在催化过程中容易溶解和聚集等。针对上述问题,本文发展了一种通用简单的合成方法,制备了还原氧化石墨烯(rGO)负载金(Au)、铂(Pt)、钯(Pd)纳米团簇的杂化材料体系,该方法利用rGO自身还原性,无需外加保护剂和还原剂。实验证明,rGO与Au纳米团簇的杂化体系具有与商业Pt/C相当的ORR活性,但更优越的抗甲醇中毒能力和稳定性。二、为获得高性能电容脱盐电极材料,本文发展了一种简单通用的方法制备三维石墨烯气凝胶与氧化物纳米粒子复合体系,氧化物包括氧化钛(TiO2)、氧化铈(CeO2)、氧化铁(α-Fe2O3)和四氧化三锰(Mn3O4)。数据表明作为高性能电容脱盐电极材料,石墨烯气凝胶负载TiO2纳米粒子体系具有高的电吸附量,快的吸附速率和稳定吸脱附循环性能。对比试验证明石墨烯气溶胶的三维贯穿网络结构,以及与TiO2纳米粒子的结合极大提高了复合体系电容脱盐吸附量和吸脱附速率,为制备高性能电容脱盐电极材料提供了设计思路。此复合材料体系也有望应用在电容熵值发电等新兴能源器件。三、为获得高性能碱性电化学产氢催化剂,本文设计合成了二维单层氢氧化镍负载一维超细铂纳米线(Pt NWs/SL-Ni(OH)2)的新型复合体系。研究发现单层结构的氢氧化镍是在其表面生成直径为1.8 nm超细铂纳米线的关键因素。实验证明Pt NWs/SL-Ni(OH)2在碱性条件下具有优异的电化学催化产氢性能。Pt NWs/SL-Ni(OH)2是第一例基于单层氢氧化物构筑的杂化体系,这一工作有望拓展基于单层氢氧化物杂化材料相关研究。
[Abstract]:After ten years of research progress has been made on graphene as the representative of two-dimensional materials, and the concept of two-dimensional materials has also penetrated into various fields. At present, it is an important research direction to design and construct nanohybrid systems based on two-dimensional materials. The development of nano-hybrid system based on two-dimensional materials can not only have a deeper understanding of the physical and chemical properties of two-dimensional materials, but also expand the application of two-dimensional materials and functional materials with them. In this paper, a new synthesis method was developed to construct a novel nano-hybrid system based on two-dimensional materials for some important electrochemical processes in the field of energy and environment, and to improve the electrochemical performance of the hybrid system by fully combining the characteristics of two-dimensional materials. The main results are as follows: firstly, compared with the large size gold nanoparticles, the gold nanoclusters with diameter less than 2 nanometers have higher oxygen catalytic reduction (ORR) activity. However, there are some problems in the practical application of gold nanoclusters, such as the reduction of ORR activity and the easy dissolution and aggregation of residual coating agents after synthesis. In order to solve the above problems, a general and simple synthesis method has been developed in this paper. The hybrid material system of reduced graphene oxide (RGO) supported au / au, Pt / PtT, PD / PD nanoclusters has been prepared. In this method, rGO itself is used to reduce the materials. No additional protectant and reductant are required. The results showed that the hybrid system of RGO and au nanoclusters had the same ORR activity as commercial Pt/C, but had superior ability and stability against methanol poisoning. Secondly, in order to obtain the high performance capacitive desalting electrode material, a simple and universal method was developed to prepare the composite system of three dimensional graphene aerogel and oxide nanoparticles. The oxides include titanium oxide TiO2, cerium oxide CeO2, ferric oxide (伪 -Fe _ 2O _ 3) and manganese trioxide (mn _ 3O _ 4). The results show that the graphene aerogel supported TiO2 nanoparticles have high electrosorption capacity, fast adsorption rate and stable desorption cycle as high performance capacitive desalination electrode materials. The results show that the three-dimensional penetration network structure of graphene aerosol and the combination of graphene aerosol with TiO2 nanoparticles greatly improve the capacitance desalination capacity and desorption rate of the composite system. The design idea is provided for the preparation of high performance capacitor desalting electrode material. The composite system is also expected to be used in new energy devices such as capacitive entropy power generation. Third, in order to obtain high performance alkaline electrochemical hydrogen production catalyst, a novel composite system supported by two-dimensional single layer nickel hydroxide supported one-dimensional ultrafine platinum nanowire Pt NWs / SL-NiOHH2) has been designed and synthesized. It is found that nickel hydroxide with monolayer structure is the key factor for the formation of 1.8 nm ultrafine platinum nanowires on its surface. The results show that Pt NWs/SL-Ni(OH)2 has excellent electrochemical catalytic hydrogen production performance under alkaline condition. Pt NWs/SL-Ni(OH)2 is the first hybrid system based on monolayer hydroxide, which is expected to expand the research on monolayer hydroxide hybrid materials.
【学位授予单位】：清华大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TB383.1

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