基于TNTAs的纳米异质薄膜光催化材料的制备与性能研究
发布时间：2018-07-23 13:11
【摘要】：光催化氧化技术由于其具有高效无污染等优点受到广大研究者的关注,提高光催化性能和实现可回收利用,是将光催化技术推向实际应用的关键。本文通过将BiOBr和有序Ti02纳米管阵列(TNTAs)薄膜进行复合形成异质结,实现将BiOBr较强的可见光光催化性能和稳定性与Ti02纳米管阵列的可回收利用性相结合,获得结合了两者优点的BiOBr/TiO2纳米异质阵列薄膜光催化剂。由于BiOBr对可见光的响应有限,并在此基础上对其进行贵金属Pt修饰进一步提高其可见光光催化性能。主要研究结果如下：(1)以氟化铵的乙二醇溶液为电解液,通过阳极氧化法在60 V电压下氧化6h制备获得有序Ti02纳米管阵列薄膜。通过改变电解液中的水含量来研究其对Ti02纳米管阵列管间距的影响。结果表明水含量的最佳参数为7%,该条件下制备的Ti02纳米管阵列管径约为150 nm,管与管之间的间隙清晰可见,并且阵列薄膜不易从基底上脱落。(2)采用循环浸渍法制备了BiOBr/TiO2纳米异质阵列薄膜(BiOBr/TNTAs),并研究不同的影响因素如反应物浓度、水浴温度、浸渍时间、浸渍遍数对其影响。结果表明最佳的制备工艺参数为：反应物浓度0.5 mM,水浴温度40℃,浸渍时间2 min,浸渍遍数2遍。对于此条件下制备的BiOBr/TNTAs,可以观察到在Ti02纳米管内外表面上负载了大量细小的纳米片,并且纳米管的管口和管间距仍清晰可见。另外研究了BiOBr/TNTAs的光催化性能,并对其机理进行了分析。结果表明BiOBr/TNTAs-2样品的光催化性能最佳,其原因可归结为以下几个因素：BiOBr对可见光的吸收,BiOBr/TNTAs异质结的形成,较大的比表面积。在以上几个因素的共同作用下,促使BiOBr/TNTAs-2样品具有较好的可见光响应和较高的量子利用效率,从而使得其具有优异的光催化性能。(3)通过溶剂热法引入贵金属Pt。首先通过实验分析确定Pt和BiOBr的沉积顺序,结果表明通过先沉积Pt后沉积BiOBr来制备Pt-BiOBr/TiO2纳米异质阵列薄膜(Pt-BiOBr/TNTAs)的实验顺序较为合理。其次研究了不同的氯铂酸浓度对样品形貌的影响,结果表明,随着氯铂酸浓度的增加,Pt纳米颗粒的数量和尺寸增加,当浓度过大时,纳米颗粒开始团聚在一起,将管口覆盖,从而选定了氯铂酸的最佳浓度为2 mM。最后研究了BiOBr沉积过程中浸渍遍数对其形貌和性能的影响并对其机理进行了分析。结果表明随着浸渍遍数的增加,BiOBr纳米片的沉积量随之上升,并且过量的负载会导致纳米管的堵塞。浸渍遍数为2的Pt-BiOBr/TNTAs-2具有最佳的光催化性能,并得出Pt-BiOBr/TNTAs-2光催化性能最佳的原因可归结于以下几个因素：①Pt的等离子共振效应使得Pt可以吸收可见光,并且可以作为电子陷阱俘获电子,②BiOBr的可见光响应,③Pt和BiOBr适当的负载量使得其具有较大的比表面积,④Pt-BiOBr/TNTAs中不同种类的异质结的形成促进了光生电子空穴对的分离。
[Abstract]:Photocatalytic oxidation technology has attracted many researchers' attention because of its high efficiency and no pollution. Improving photocatalytic performance and realizing recycling is the key to the application of photocatalytic technology. In this paper, BiOBr and ordered Ti02 nanotube array (TNTAs) films are combined to form heterojunction to combine the strong visible photocatalytic properties and stability of BiOBr with the recyclability of Ti02 nanotube arrays. The photocatalyst of BiOBr/TiO2 nanoscale heterostructure array film was obtained by combining the advantages of both. Because the response of BiOBr to visible light is limited, and on the basis of this, the Pt modification of BiOBr can further improve the photocatalytic performance of visible light. The main results are as follows: (1) the ordered Ti02 nanotube array films were prepared by anodic oxidation at 60 V voltage with ethylene glycol solution of ammonium fluoride as electrolyte. The effect of water content on the spacing of Ti02 nanotube arrays was studied by changing the water content in the electrolyte. The results show that the optimum parameter of water content is 7 and the diameter of the Ti02 nanotube array is about 150nm.The gap between the tubes is clearly visible. The BiOBr/TiO2 nanoscale heterostructure array (BiOBr/TNTAs) thin films were prepared by cyclic impregnation method. The effects of different factors such as reactant concentration, water bath temperature, impregnation time and number of impregnation times on it were studied. The results showed that the optimum preparation parameters were as follows: reactant concentration 0.5 mm, water bath temperature 40 鈩，
本文编号：2139518
[Abstract]:Photocatalytic oxidation technology has attracted many researchers' attention because of its high efficiency and no pollution. Improving photocatalytic performance and realizing recycling is the key to the application of photocatalytic technology. In this paper, BiOBr and ordered Ti02 nanotube array (TNTAs) films are combined to form heterojunction to combine the strong visible photocatalytic properties and stability of BiOBr with the recyclability of Ti02 nanotube arrays. The photocatalyst of BiOBr/TiO2 nanoscale heterostructure array film was obtained by combining the advantages of both. Because the response of BiOBr to visible light is limited, and on the basis of this, the Pt modification of BiOBr can further improve the photocatalytic performance of visible light. The main results are as follows: (1) the ordered Ti02 nanotube array films were prepared by anodic oxidation at 60 V voltage with ethylene glycol solution of ammonium fluoride as electrolyte. The effect of water content on the spacing of Ti02 nanotube arrays was studied by changing the water content in the electrolyte. The results show that the optimum parameter of water content is 7 and the diameter of the Ti02 nanotube array is about 150nm.The gap between the tubes is clearly visible. The BiOBr/TiO2 nanoscale heterostructure array (BiOBr/TNTAs) thin films were prepared by cyclic impregnation method. The effects of different factors such as reactant concentration, water bath temperature, impregnation time and number of impregnation times on it were studied. The results showed that the optimum preparation parameters were as follows: reactant concentration 0.5 mm, water bath temperature 40 鈩，
本文编号：2139518
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