碳点与二氧化钛体系光催化性能研究

发布时间：2018-06-08 03:44

本文选题：碳点 + 二氧化钛　；参考：《西南石油大学》2017年硕士论文

【摘要】：氢能作为一种理想的无污染绿色能源,能够有效缓解能源和环境双重危机。而利用太阳能光催化分解水制氢是获得廉价氢能的理想途径之一。设计出可见光吸收,催化活性和稳定性高的光催化剂是光催化制氢研究的关键。碳点具有可调的光学特性、优异的电子传输能力以及丰富的来源,因而在光催化制氢领域有极大的应用前景。本课题采用水热、电化学和超声方法合成碳点,对比不同方法制备的碳点与P25TiO_2复合体系的光催化降解氮氧化物测试结果,确定碳点制备的最佳方法为水热法。进一步地研究水热碳点与二氧化钛复合体系的光催化制氢性能。发现水热碳点只对{001}TiO_2催化制氢性能有提升作用,而其它二氧化钛如P25TiO_2,锐钛矿,{101}TiO_2和{100}TiO_2的光催化制氢活性都受到明显的抑制。基于上述现象,深入研究了水热碳点与{001}TiO_2相互作用下的光催化制氢过程,结果表明,当碳点负载量为0.5 wt%时,对{001}TiO_2产氢活性提升效果最为显著,主要归因于碳点对电子较高的传输能力以及电子和空穴良好的分离作用。并且体系表现出相当好的稳定性。掺杂改性是提高碳点光催化性能的有效手段,因此通过引入N、S和B原子从而调控碳点的光学性质。发现杂原子的引入可以促进碳点的可见吸收。在此基础上,掺杂碳点修饰的TiO_2其可见光催化制氢性能也得到一定提升。综上,本课题通过探索碳点的合成并对其进行修饰,研究碳点与二氧化钛复合体系的光催化制氢性能,能够为设计和开发出基于碳点的高效催化剂提供一定依据。
[Abstract]:As an ideal green energy, hydrogen energy can effectively alleviate the dual crisis of energy and environment. The photocatalytic decomposition of water for hydrogen production by solar energy is one of the ideal ways to obtain low-cost hydrogen energy. The key to the study of hydrogen production is to design photocatalysts with high visible light absorption, catalytic activity and stability. Because of its tunable optical properties, excellent electron transport and abundant sources, carbon dots have great application prospects in the field of photocatalytic hydrogen production. In this paper, hydrothermal, electrochemical and ultrasonic methods were used to synthesize carbon points. The results of photocatalytic degradation of nitrogen oxides in P25TiO2 composite system prepared by different methods were compared. The best method for preparing carbon points was hydrothermal method. The photocatalytic hydrogen production properties of hydrothermal carbon point and titanium dioxide composite system were further studied. It is found that the hydrothermal carbon point can only enhance the catalytic activity of {001} TiO2 to produce hydrogen, while the photocatalytic activity of other titanium dioxide such as P25TiO2, anatase, {101} TIO _ 2 and {100} TIO _ 2 are obviously inhibited. Based on the above phenomena, the photocatalytic hydrogen production process under the interaction of hydrothermal carbon point and {001} TiOs _ 2 is studied. The results show that when the loading amount of carbon point is 0.5 wt%, the effect of increasing hydrogen production activity of {001} TIO _ 2 is the most significant. It is mainly attributed to the high transport ability of carbon points to electrons and the good separation of electrons and holes. And the system shows quite good stability. Doping modification is an effective means to improve the photocatalytic performance of carbon points. Therefore, the optical properties of carbon spots are regulated by introducing Nos and B atoms. It is found that the introduction of heteroatoms can promote the visible absorption of carbon points. On this basis, the visible light catalytic hydrogen production performance of TiO2 modified by carbon dots was also improved to a certain extent. In summary, the photocatalytic hydrogen production of the composite system of carbon point and titanium dioxide can be studied by exploring the synthesis and modification of carbon point, which can provide some basis for the design and development of high efficiency catalyst based on carbon point.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36;TQ116.2

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