光催化甘油水溶液制氢性能研究

发布时间：2018-02-13 08:25

  本文关键词： 光催化剂 Pt 甘油重整 NiS/CdS 机理　出处：《淮北师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：通过光沉积(PD)和浸渍还原沉积(IRD)的方法，制备了系列Pt修饰TiO2光催化剂，系统考察沉积方法对Pt的特性以及样品光催化重整甘油产氢活性的影响；其次通过简单的两步法合成了系列NiS负载CdS光催化剂，比较分析了催化剂本体形貌以及负载助催化剂对产氢活性的影响。分别采用XRD、UV-vis DRS、SEM、TEM、BET、XPS、PL等表征技术对上述样品进行表征分析。结果表明，Pt/TiO2重整甘油产氢的活性高度依赖于助催化剂Pt的特性，这些特性包括Pt的化学价态、尺寸大小以及与TiO2结合的紧密程度。Pt的这些特性一方面影响基底TiO2捕获光子的能力外，另一方面，其与TiO2形成的肖特基势垒还会影响光生电子从TiO2往Pt的迁移，最后不同价态的Pt还影响氢的析出；通过原位光沉积法所得的样品Pt均匀分布于TiO2表面的电子捕获位，与基底TiO2结合紧密，且Pt的表面和体相均呈零价态，，这些特性有助于电子及时从TiO2表面转移至Pt以及氢的析出，从而表现出较高的产氢活性。而通过其它的沉积方法所得的样品，Pt颗粒在TiO2表面随机分布，其体相主要呈氧化态，不利于捕获TiO2光生电子，因此产氢活性较低；对于NiS/CdS样品，研究结果显示，水热温度为200℃下合成的样品呈花簇状，负载1.5wt.%助催化剂NiS产氢活性最高，甚至超过同等条件下Pt/CdS产氢活性。通过对机理的研究表明，NiS的负载能使电子与空穴有效的分离，并充当产氢活性位。因此，产氢活性的提高取决于本体催化剂的制备方法和助催化剂的共同作用。
[Abstract]:Through the optical deposition (PD) and impregnation deposition (IRD) method, a series of Pt modified TiO2 photocatalyst was prepared, system of deposition method on Pt and influence the photocatalytic activity of glycerol reforming hydrogen production; followed by two step simple synthesize a series of NiS loaded CdS photocatalyst, comparative analysis the catalyst body morphology and load cocatalyst on the effects of hydrogen production activity. Using the XRD, UV-vis DRS, SEM, TEM, BET, XPS, to characterize the samples of PL were characterized. The results show that the characteristics of Pt/TiO2 hydrogen production activity of glycerol is highly dependent on the promoter of Pt, these properties include chemical the valence states of Pt, capacity size and TiO2 combined with the close degree of.Pt on the one hand, these characteristics influence of substrate TiO2 capture photons, on the other hand, the Schottky barrier and the formation of TiO2 also affects the photogenerated electrons from TiO2 to Pt migration, finally different valence Pt also affected the hydrogen evolution; electron capture through the sample from Pt in situ optical deposition evenly distributed on the surface of TiO2, combined with TiO2 and Pt of the substrate, the surface and bulk phase showed zero valence, these features contribute to the electronic and from the surface of the TiO2 transfer to Pt and hydrogen evolution, which showed a high activity of hydrogen production. Through other methods the sediment samples of Pt particles on the surface of TiO2 random distribution, the main body is not conducive to the oxidation state, TiO2 capture photogenerated electrons, so the hydrogen production activity is relatively low; for the NiS/CdS sample the results of the study show that, the temperature is 200 DEG C in synthetic samples clustered, supported 1.5wt.% promoter of NiS hydrogen production activity is highest, even more than Pt/CdS under the same conditions of hydrogen production activity. Through the research on the mechanism that NiS load can make the electrons and holes are Therefore, the improvement of hydrogen production depends on the preparation method of the bulk catalyst and the co action of the catalyst.

【学位授予单位】：淮北师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ116.2;O643.36

【参考文献】

相关期刊论文 前4条

1 杨儒,李敏,张敬畅,曹维良,胡天斗,张静;锐钛矿型纳米TiO_2粉体的精细结构及其光催化降解苯酚的活性[J];催化学报;2003年08期

2 付贤智,李旦振;提高多相光催化氧化过程效率的新途径[J];福州大学学报(自然科学版);2001年06期

3 郑红，汤鸿霄，王怡中;有机污染物半导体多相光催化氧化机理及动力学研究进展[J];环境科学进展;1996年03期

4 魏子栋,殷菲,谭君,WalterZ.Tang,侯万国;TiO_2光催化氧化研究进展[J];化学通报;2001年02期

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