發(fā)布時間：2018-05-03 20:24

  本文選題：金基異質納米結構 + 光學性質　； 參考：《山東大學》2015年碩士論文

【摘要】：金納米顆粒具有獨特可調的光學性質,令其在光學檢測、生物成像、光熱治療等很多領域內具有廣闊的應用前景。該光學性質可以通過改變納米顆粒的結構、尺寸或成分進行調控。形成異質結構是引入外來成分、改變原有結構的一種有效手段。異質結構不僅集合了單一材料的性能,同時還有不同材料有效組裝后的獨特性能。本文通過擇優(yōu)腐蝕方法得到了多種新穎的金基異質納米結構,并對反應產物的結構和成分進行了詳細的表征,通過UV-vis消光光譜對其反應過程進行了仔細的研究,對反應機制提出了較為合理的推測并加以驗證。本論文的主要研究內容是：1.以金納米棒為模板,在銀離子的調控下,通過K2PtCl4對金納米棒的側面腐蝕反應,實現(xiàn)了金納米棒光學性質的有效調控,并最終得到了啞鈴狀的PtAu-Au納米棒。通過一系列對比試驗發(fā)現(xiàn),K2PtCl4與單質金的氧化還原反應優(yōu)先發(fā)生在金納米棒活性較高的兩端。由于兩端CTAB分子包覆的較少,被還原的Pt0可以沉積在兩端,從而阻礙了兩端的進一步反應。銀離子的存在引起金納米棒側面的CTAB濃度升高,不利于還原出的Pto在側面沉積,所以側面的Au可以持續(xù)被氧化,導致金納米棒的直徑有效削減。相比較金納米棒和核-殼納米棒,這種新形成的較細的啞鈴狀Pt/Au納米棒在對硝基苯酚的還原中,表現(xiàn)了更高的催化活性。這種催化活性的提高來自于啞鈴狀Pt/Au納米棒的獨特結構和電子效應。2.以金納米球為模板,通過其與AgNO3、HAuCl4、K2PtCl4以及AA之間的反應,成功地制備了一種新穎的Au@PtAuAg異質納米顆粒。通過一系列的對比試驗發(fā)現(xiàn),Au(Ⅲ)/Au和Ag(Ⅰ)/Ag具有較高的標準電極電勢,AuAg首先在金納米球上生長得到八面體狀的Au@AuAg結構模板,隨后Pt2+被AA還原,沉積在Au@AuAg納米顆粒的頂點,而溶液中過量的HAuCl4對Au@AuAg八面體中未被Pt覆蓋的區(qū)域進行腐蝕,從而得到了新穎的Au@PtAuAg異質納米顆粒。因為Pt本身具有良好的催化性質,所以這種Au@PtAuAg異質納米顆粒,在催化方面有著潛在的應用價值。
[Abstract]:Due to its unique and adjustable optical properties, gold nanoparticles have broad application prospects in many fields, such as optical detection, biological imaging, photothermal therapy and so on. The optical properties can be regulated by changing the structure, size or composition of nanoparticles. The formation of heterogeneous structure is an effective means to introduce foreign elements and change the original structure. Heterostructures not only aggregate the properties of a single material, but also exhibit unique properties after effective assembly of different materials. In this paper, a variety of novel gold based heterostructures were obtained by preferential etching method. The structure and composition of the products were characterized in detail, and the reaction process was studied by UV-vis extinction spectroscopy. A reasonable conjecture of the reaction mechanism was put forward and verified. The main content of this thesis is 1: 1. The optical properties of gold nanorods were effectively controlled by K2PtCl4 under the control of silver ions, and the dumbbell shaped PtAu-Au nanorods were obtained. Through a series of comparative experiments, it was found that the redox reaction of K2PtCl4 with simple gold occurred preferentially at the ends of the gold nanorods with higher activity. The reduced Pt0 can be deposited at both ends due to the less encapsulation of CTAB molecules at both ends, which hinders the further reaction at both ends. The presence of silver ions increases the concentration of CTAB on the side of the gold nanorods, which is not conducive to the deposition of the reduced Pto on the side, so the au on the side can be continuously oxidized, leading to the effective reduction of the diameter of the gold nanorods. Compared with gold nanorods and core-shell nanorods, the new dumbbell shaped Pt/Au nanorods exhibit higher catalytic activity in the reduction of p-nitrophenol. The improvement of catalytic activity comes from the unique structure and electronic effect of dumbbell Pt/Au nanorods. Using gold nanospheres as template, a novel Au@PtAuAg heterogeneous nanoparticles were successfully prepared by the reaction of Agno _ 3H _ AuCl _ 4N _ 2PtCl _ 4 with Agno _ 3H _ AuCl _ 4H _ 2PtCl _ 4 and AA. Through a series of comparative tests, it was found that au (鈪，

本文編號：1839954