掺杂中空碳纳米球的制备及其在电催化氧还原反应中的应用

发布时间：2018-06-22 19:27

  本文选题：中空碳纳米球 + 掺杂　； 参考：《东南大学》2015年硕士论文

【摘要】：随着全球环境污染的日趋加剧,能源危机的日益严重,人口的快速增长和经济的高速发展,人类更加依赖于可持续发展的新型能源。备受关注的燃料电池作为新型能源有高的转化效率及环境污染小等特点。然而燃料电池中的铂基催化剂因稳定性差、抗甲醇毒性差、成本高及自然资源不足等问题限制了其商业化进程。近几年来,杂原子掺杂的碳材料被广泛应用于氧气催化还原反应中。在催化、医药、储能等应用领域上,空心碳球因具有高比表面积、密度低、化学稳定性好、导电性好等特性而拥有着巨大的应用价值。本论文主要设计并合成了硼掺杂中空碳纳米球,氮掺杂中空碳纳米球及硼、氮共掺杂中空碳纳米球,并将其应用于燃料电池阴极氧气还原反应中。主要包括以下几个部分：1.采用一种简单温和的水热反应,通过对调节对羟基苯硼酸和间苯二酚的比例及煅烧温度等条件,制备得到硼掺杂的中空碳球。实验通过扫描电镜、透射电镜、拉曼、X射线光电子能谱、热重、动态光散射、比表面积分析等对材料进行了详细表征。材料在煅烧前后形貌不变,粒径均一,为直径约200 nm的中空碳纳米球。2.用合成的硼掺杂中空碳纳米球修饰电极,循环伏安法(CV)、线性扫描检(LSV)测碱性溶液中材料对氧气催化的还原电流。比较不同合成条件对电流和电位的影响,发现随着煅烧温度的增加,还原电流不断增加且在900℃时达到最大值,此时还原峰电位最正。同时对羟基苯硼酸和间苯二酚的比例也对催化电流产生影响,在3：7时达到催化性能最佳,随后通过表征材料的结构性能研究解释了这一变化规律。3.将由上述方法合成的硼掺杂中空碳纳米球与尿素在高温煅烧下复合,通过调节煅烧温度制得硼、氮共掺杂的中空碳纳米球。实验通过扫描电镜、透射电镜、拉曼、X射线光电子能谱、热重、红外、比表面积分析等对材料进行了详细表征。共掺杂后中空碳纳米球的形貌没变,但比表面积明显增大。4.用合成的硼、氮掺杂的中空碳纳米球修饰电极,循环伏安法(CV)、线性扫描(LSV)检测碱性溶液中材料对氧气催化的还原电流。比较不同合成条件对电流和电位的影响发现,煅烧温度对材料的氧还原催化活性有很大影响。通过表征材料的结构性能研究解释了这一变化规律。比较硼、氮共掺杂中空碳纳米球和硼掺杂中空碳纳米球以及氮掺杂中空碳纳米球发现,共掺杂的中空碳纳米球拥有更好的氧还原性能,具有潜在的应用前景。
[Abstract]:With the worsening of global environmental pollution, the increasingly serious energy crisis, the rapid growth of population and the rapid development of economy, human beings rely more and more on the sustainable development of new energy. As a new type of energy, fuel cell has the characteristics of high conversion efficiency and low environmental pollution. However, due to poor stability, poor methanol toxicity, high cost and insufficient natural resources, platinum based catalysts in fuel cells have limited their commercialization process. In recent years, hetero-doped carbon materials have been widely used in oxygen catalytic reduction. In the fields of catalysis, medicine and energy storage, hollow carbon spheres have great application value because of their high specific surface area, low density, good chemical stability and good electrical conductivity. In this paper, boron doped hollow carbon nanospheres, nitrogen doped hollow carbon nanospheres and boron, nitrogen co-doped hollow carbon nanospheres were designed and synthesized. Mainly include the following parts: 1. Boron doped hollow carbon spheres were prepared by adjusting the ratio of p-hydroxyphenylboric acid and resorcinol and calcining temperature in a simple and mild hydrothermal reaction. The materials were characterized by scanning electron microscope, transmission electron microscope, Raman X-ray photoelectron spectroscopy, thermogravimetry, dynamic light scattering and specific surface area analysis. Before and after calcination, the material has the same morphology and uniform particle size, which is a hollow carbon nanospheres with a diameter of about 200 nm. Boron doped hollow carbon nanospheres were used to modify the electrode, cyclic voltammetry (CV) and linear scanning voltammetry (LSV) were used to determine the oxygen reduction current in alkaline solution. By comparing the effects of different synthesis conditions on the current and potential, it is found that with the increase of calcination temperature, the reduction current increases and reaches the maximum at 900 鈩，

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