發(fā)布時(shí)間：2018-05-03 20:24

  本文選題：金基異質(zhì)納米結(jié)構(gòu) + 光學(xué)性質(zhì)��； 參考：《山東大學(xué)》2015年碩士論文

【摘要】：金納米顆粒具有獨(dú)特可調(diào)的光學(xué)性質(zhì),令其在光學(xué)檢測(cè)、生物成像、光熱治療等很多領(lǐng)域內(nèi)具有廣闊的應(yīng)用前景。該光學(xué)性質(zhì)可以通過(guò)改變納米顆粒的結(jié)構(gòu)、尺寸或成分進(jìn)行調(diào)控。形成異質(zhì)結(jié)構(gòu)是引入外來(lái)成分、改變?cè)�有結(jié)構(gòu)的一種有效手段。異質(zhì)結(jié)構(gòu)不僅集合了單一材料的性能,同時(shí)還有不同材料有效組裝后的獨(dú)特性能。本文通過(guò)擇優(yōu)腐蝕方法得到了多種新穎的金基異質(zhì)納米結(jié)構(gòu),并對(duì)反應(yīng)產(chǎn)物的結(jié)構(gòu)和成分進(jìn)行了詳細(xì)的表征,通過(guò)UV-vis消光光譜對(duì)其反應(yīng)過(guò)程進(jìn)行了仔細(xì)的研究,對(duì)反應(yīng)機(jī)制提出了較為合理的推測(cè)并加以驗(yàn)證。本論文的主要研究?jī)?nèi)容是：1.以金納米棒為模板,在銀離子的調(diào)控下,通過(guò)K2PtCl4對(duì)金納米棒的側(cè)面腐蝕反應(yīng),實(shí)現(xiàn)了金納米棒光學(xué)性質(zhì)的有效調(diào)控,并最終得到了啞鈴狀的PtAu-Au納米棒。通過(guò)一系列對(duì)比試驗(yàn)發(fā)現(xiàn),K2PtCl4與單質(zhì)金的氧化還原反應(yīng)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(jìn)一步反應(yīng)。銀離子的存在引起金納米棒側(cè)面的CTAB濃度升高,不利于還原出的Pto在側(cè)面沉積,所以側(cè)面的Au可以持續(xù)被氧化,導(dǎo)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(xì)的啞鈴狀Pt/Au納米棒在對(duì)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(lái)自于啞鈴狀Pt/Au納米棒的獨(dú)特結(jié)構(gòu)和電子效應(yīng)。2.以金納米球?yàn)槟０?通過(guò)其與AgNO3、HAuCl4、K2PtCl4以及AA之間的反應(yīng),成功地制備了一種新穎的Au@PtAuAg異質(zhì)納米顆粒。通過(guò)一系列的對(duì)比試驗(yàn)發(fā)現(xiàn),Au(Ⅲ)/Au和Ag(Ⅰ)/Ag具有較高的標(biāo)準(zhǔn)電極電勢(shì),AuAg首先在金納米球上生長(zhǎng)得到八面體狀的Au@AuAg結(jié)構(gòu)模板,隨后Pt2+被AA還原,沉積在Au@AuAg納米顆粒的頂點(diǎn),而溶液中過(guò)量的HAuCl4對(duì)Au@AuAg八面體中未被Pt覆蓋的區(qū)域進(jìn)行腐蝕,從而得到了新穎的Au@PtAuAg異質(zhì)納米顆粒。因?yàn)镻t本身具有良好的催化性質(zhì),所以這種Au@PtAuAg異質(zhì)納米顆粒,在催化方面有著潛在的應(yīng)用價(jià)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(hào)：1839954