钽酸盐光催化剂的合成及其光催化分解水制氢性能的研究

发布时间：2018-04-17 21:34

本文选题：钽酸盐 + 不同形貌　；参考：《南昌航空大学》2015年硕士论文

【摘要】：化石燃料仍是目前人类的主要能源,近几个世纪以来,蓬勃发展的工业带来了大量的污染物。CO2作为温室气体之一,是全球变暖的主要原因。直接将太阳能转化为化学能而无CO2的排放,仍是目前研究学者们一个美好的愿望。自1972年Fujishima和Honda首次报道半导体在紫外光下可以分解水以来,光催化剂的研究吸引了广泛的注意,将太阳能转化为干净的氢能被大量的研究。然而,在众多光催化分解水系统中,提高太阳能的转化率和产氢效率仍是一项巨大的挑战。本论文研究了不同形貌的InTaO4和CdS/Bi1-xInx TaO4异质结光催化剂及其光催化分解水的性能。我们首次通过一种多功能的溶胶前驱体成功制备了InTaO4纳米粒、SiO2@InTaO4核壳纳米球和InTaO4纳米线光催化剂,钽酸铟不同的形貌展现出了不同的物理化学性质。其中,InTaO4纳米线光催化剂表现出了更高的光吸收、更大比表面积以及更好的光催化产氢活性,其在模拟太阳光照射下的光催化产氢速率为29.92μmol·g-1·h-1。并提出了不同形貌InTaO4光催化剂的一个可能的形成机制和可能的光催化反应机理。本研究对不同形貌的光催化剂在环境和能源方面的应用提供了一项新进展。我们采用更便宜的Ta2O5原材料,通过溶胶-凝胶法合成了一系列的Bi1-xInxTaO4(x=0、0.1、0.3、0.5、0.7、0.9和1.0)光催化剂,并且采用简单的CdS作为助催化剂合成了不同含量的CdS负载的CdS/Bi0.5In0.5TaO4异质结复合光催化剂。实验结果表明,Bi0.5In0.5TaO4光催化剂比其它的Bi1-xInxTaO4光催化剂有着更好的光催化活性,并且,30%CdS/Bi0.5In0.5TaO4(30CBITO)异质结光催化剂展示出了最好的光催化产氢活性,在模拟太阳光下的产氢速率达到了808.01μmol·h-1·g-1,而且,30%CdS/Bi0.5In0.5TaO4光催化剂在经历了60个小时的光催化周期反应后,产氢速率仍然没有明显的衰减。我们还通过紫外可见漫反射(DRS)、X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)以及高分辨率透射电子显微镜(HRTEM)对光催化剂的物理化学性质进行了表征研究。一个可能的增强光催化反应活性的机理被提出,并阐明了异质结结构的CdS/Bi0.5In0.5TaO4光催化剂优越的光催化产氢活性和长效的稳定性。本研究工作为提高没有贵金属助催化剂的钽酸盐光催化剂的产氢性能开辟了一条新的道路。
[Abstract]:Fossil fuels are still the main energy of human beings. In recent centuries, the booming industry has brought a large number of pollutants. CO2 as one of the greenhouse gases, is the main cause of global warming.Direct conversion of solar energy to chemical energy without CO2 emissions is still a good wish of researchers.Since 1972, when Fujishima and Honda first reported that semiconductors can decompose water under ultraviolet light, the study of photocatalysts has attracted extensive attention. The conversion of solar energy to clean hydrogen energy has been studied extensively.However, in many photocatalytic water decomposition systems, increasing the conversion of solar energy and the efficiency of hydrogen production is still a great challenge.In this paper, the hetero-junction photocatalysts of InTaO4 and CdS/Bi1-xInx TaO4 with different morphologies and their photocatalytic properties for water decomposition have been studied.For the first time, we successfully prepared InTaO4 nanocrystalline SiO2 @ InTaO4 core-shell nanospheres and InTaO4 nanowire photocatalysts through a multifunctional sol precursor. Different morphologies of indium tantalate show different physical and chemical properties.InTaO4 nanowire photocatalyst exhibits higher photoabsorption, larger specific surface area and better photocatalytic hydrogen production activity. The photocatalytic hydrogen production rate under simulated solar irradiation is 29.92 渭 mol g-1 h-1.A possible formation mechanism and a possible photocatalytic reaction mechanism of InTaO4 photocatalysts with different morphologies were also proposed.This study provides a new development in environmental and energy applications of photocatalysts with different morphologies.We have synthesized a series of Bi1-xInxTaO4xO4xO4xO0O0O0OO0O0O01O1O3O5O0.70.9-and 1.0) photocatalysts using cheaper Ta2O5 raw materials, and used simple CdS as co-catalyst to synthesize CdS/Bi0.5In0.5TaO4 heterojunction photocatalysts supported on different contents of CdS.The experimental results show that Bi0.5In0.5TaO4 photocatalyst has better photocatalytic activity than other Bi1-xInxTaO4 photocatalysts, and the 30s / Bi0.5In0.5TaO4 / 30CBITO heterojunction photocatalyst exhibits the best photocatalytic activity for hydrogen production.The hydrogen production rate reached 808.01 渭 mol h-1 g-1 under simulated solar light, and the hydrogen production rate of 30s / Bi0.5In0.5TaO4 photocatalyst did not decrease significantly after 60 hours of photocatalytic periodic reaction.The physical and chemical properties of the photocatalysts were also characterized by UV-Vis diffuse reflectance (DRS) X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM).A possible mechanism for enhancing photocatalytic activity has been proposed, and the excellent photocatalytic activity and long-term stability of heterojunction CdS/Bi0.5In0.5TaO4 photocatalysts have been elucidated.This work opens a new way to improve the hydrogen production performance of tantalate photocatalyst without noble metal catalyst.
【学位授予单位】：南昌航空大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ116.2;O643.36

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