Ti基钙钛矿氧化物的生长及光催化性能研究

发布时间：2018-03-18 09:19

本文选题：钙钛矿氧化物　切入点：反应机理　出处：《西南石油大学》2017年硕士论文　论文类型：学位论文

【摘要】：ABO3型钙钛矿是钙钛矿家族中的重要成员,由于其A位元素的多变性,可表现出丰富的物理、化学性质,进而被广泛应用于气体传感器,电容器,光致制动器,染料敏化电池以及光催化剂。本文探索了使用纳米片状锐钛矿型TiO2作为钛源,模板法水热合成ATiO3(A = Ba,Pb和Sr)。在该水热条件下,由于A位元素的不同,产物ATiO3表现出不同的结构与性能。通过X射线衍射(XRD),扫描电子显微镜(SEM)、透射电子显微镜(TEM),选区电子衍射(SAED)等表征分析方法,对产物材料进行结构与形貌分析。采用时间分辨X射线衍射图谱,对样品进行生长机理的研究,通过分析拟合结果得出在所合成的样品 BaTiO3,PbTiO3,SrTiO3,BaxPb1-iO3 和 SrxPb1xTiO3 中,PbTiO3的生长速率最慢。在ATiO3生长过程中,以A位元素在固相表面的扩散以及固/液界面的反应占主要控制因素。在探索所有自合成样品的光催化性能过程中,发现它们均表现出光降解低浓度氮氧化合物的活性。其中,PbTiO3在全光谱和可见光(λ420nm)下活性最优主要归因于其光生载流子迁移速率较其他产物的更大;BaTiO3在NO的转化过程中表现出良好的选择性,其氧化产物中理想产物(NO3-或NO2-)所占比例最大。在光催化还原H2O制氢的实验中,SrTiO3的活性最优,且经过绿色无毒的CDs表面改性后,还原活性增强了 30%。希望本研究工作提供的有关ATiO3的光催化活性及选择性能的信息,对后期ATiO3的表面改性提供更多的线索。
[Abstract]:ABO3 perovskite is an important member of the perovskite family, the variability of the A elements, can exhibit rich physical and chemical properties, and is widely used in gas sensors, capacitors, light induced brake, dye sensitized solar cell and photocatalyst. This paper explores the use of nano scale anatase TiO2 as titanium source template method, hydrothermal synthesis of ATiO3 (A = Ba, Pb and Sr). In the hydrothermal conditions, due to the different elements of A, ATiO3 showed the product structure and properties of different. By means of X ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), constituency electron diffraction (SAED) characterization analysis method, analyzed the structure and morphology of the product material. By using time-resolved X ray diffraction, studied the growth mechanism of the sample, through the analysis of the simulation results obtained in BaTiO3 samples, the synthesis of PbTiO3, SrTiO3, BaxPb1 -iO3 and SrxPb1xTiO3, the PbTiO3 growth rate of the slowest. In the growth process of ATiO3, the A element in the diffusion of solid surface and solid / liquid interface reaction for main control factors. In the exploration of all self synthesized samples the photocatalytic performance of the process, found that they showed the degradation of low concentration of nitrogen oxides the activity of PbTiO3. Among them, the full spectrum of visible light (lambda 420nm) under optimal activity is mainly attributed to the optical carrier migration rate than other products more; BaTiO3 showed good selectivity in the NO conversion process, the ideal product in the oxidation products (NO3- or NO2-) in the largest proportion. The photocatalytic reduction of H2O hydrogen production experiments, the optimal activity of SrTiO3, and through the green non-toxic CDs after surface modification, 30%. reduction activity enhanced photocatalytic activity and selectivity in the hope that this research work will provide the ATiO3 to the Information provides more clues to the surface modification of the later ATiO3.

【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

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