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  本文關鍵詞： 光催化劑 Pt 甘油重整 NiS/CdS 機理　出處：《淮北師范大學》2015年碩士論文　論文類型：學位論文

【摘要】：通過光沉積(PD)和浸漬還原沉積(IRD)的方法，制備了系列Pt修飾TiO2光催化劑，系統(tǒng)考察沉積方法對Pt的特性以及樣品光催化重整甘油產氫活性的影響；其次通過簡單的兩步法合成了系列NiS負載CdS光催化劑，比較分析了催化劑本體形貌以及負載助催化劑對產氫活性的影響。分別采用XRD、UV-vis DRS、SEM、TEM、BET、XPS、PL等表征技術對上述樣品進行表征分析。結果表明，Pt/TiO2重整甘油產氫的活性高度依賴于助催化劑Pt的特性，這些特性包括Pt的化學價態(tài)、尺寸大小以及與TiO2結合的緊密程度。Pt的這些特性一方面影響基底TiO2捕獲光子的能力外，另一方面，其與TiO2形成的肖特基勢壘還會影響光生電子從TiO2往Pt的遷移，最后不同價態(tài)的Pt還影響氫的析出；通過原位光沉積法所得的樣品Pt均勻分布于TiO2表面的電子捕獲位，與基底TiO2結合緊密，且Pt的表面和體相均呈零價態(tài)，，這些特性有助于電子及時從TiO2表面轉移至Pt以及氫的析出，從而表現(xiàn)出較高的產氫活性。而通過其它的沉積方法所得的樣品，Pt顆粒在TiO2表面隨機分布，其體相主要呈氧化態(tài)，不利于捕獲TiO2光生電子，因此產氫活性較低；對于NiS/CdS樣品，研究結果顯示，水熱溫度為200℃下合成的樣品呈花簇狀，負載1.5wt.%助催化劑NiS產氫活性最高，甚至超過同等條件下Pt/CdS產氫活性。通過對機理的研究表明，NiS的負載能使電子與空穴有效的分離，并充當產氫活性位。因此，產氫活性的提高取決于本體催化劑的制備方法和助催化劑的共同作用。
[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.

【學位授予單位】：淮北師范大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TQ116.2;O643.36

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本文編號：1507731