發(fā)布時間：2018-06-05 11:13

  本文選題：核殼納米晶 + 表面等離子體共振效應��； 參考：《北京理工大學》2015年碩士論文

【摘要】：本論文以半導體納米晶及其與貴金屬形成的核殼納米結(jié)構(gòu)為主要研究對象，采用非外延生長法和不同膦配體誘發(fā)的陽離子交換法相結(jié)合制備了Au@CdX（X為硫?qū)僮逶兀┑暮藲そY(jié)構(gòu)納米晶，異價摻雜的CdS納米晶，并對其光分解水制氫、發(fā)光性能進行了研究。主要取得的成果及創(chuàng)新點如下： 1.我們利用非外延生長法與陽離子交換法相結(jié)合在水相中制備出具有不同厚度單晶殼層的Au@CdS核殼結(jié)構(gòu)納米晶，，且半導體CdS在三維方向上在高曲率金屬Au核納米晶表面形成直接接觸和清晰的界面�；谫F金屬局域表面等離子體共振（LSPR）效應，在入射光子的激發(fā)下，產(chǎn)生了LSPR增強下的高效電子/空穴分離及電子注入效應。對不同殼層厚度Au@CdS核殼結(jié)構(gòu)納米晶進行光分解水制氫性能的測試，當Au核尺寸增長到約為35nm時，Au35nm@CdS5nm核殼結(jié)構(gòu)納米晶的平均產(chǎn)氫速率高達24mmol·h-1·g-1，比同質(zhì)量的CdS量子點在相同時間內(nèi)產(chǎn)生的氫氣量高1000倍以上。此外，在LSPR效應作用下，隨著CdS殼層厚度的增加，核殼結(jié)構(gòu)表面的LSPR逐漸減弱。輔助于FDTD理論模擬，發(fā)現(xiàn)了plasmon增強為主導貢獻的高效光催化產(chǎn)氫原理。 2.利用不同膦配體提供給過渡金屬離子σ電子的能力不同和不同膦配體空間位阻存在差異，進而更加靈活地調(diào)節(jié)陽離子交換反應的熱力學和動力學。創(chuàng)新性發(fā)現(xiàn)不同種膦配體引發(fā)下的陽離子交換反應可用于合成更精確的半導體納米結(jié)構(gòu)，尤其是新型金屬/半導體核殼納米晶和摻雜納米晶結(jié)晶性、成分、形貌和相關的光學性質(zhì)更靈活的調(diào)控。創(chuàng)新性發(fā)現(xiàn)相比三丁基膦，三苯基膦（PPh3）作為一種能在空氣中穩(wěn)定存在、無刺激性氣味的綠色試劑，可引發(fā)陽離子交換反應，合成Au@CdS和Pt@CdS納米結(jié)構(gòu)等形成較好的結(jié)晶性和清晰的界面，Au@CdS1-xSex復合異質(zhì)結(jié)構(gòu)中的組分，以及異價摻雜引起的高效的摻雜發(fā)光調(diào)控。
[Abstract]:In this thesis, semiconductor nanocrystals and their core-shell nanostructures formed with precious metals are the main research objects. Core-shell structure nanocrystals (Au@CdX(X) and heterovalent doped CdS nanocrystals were prepared by non-epitaxial growth and cationic exchange induced by different phosphine ligands. The photoluminescence properties of CdS nanocrystals were studied. The main achievements and innovations are as follows: 1. Nanocrystalline Au@CdS core-shell structures with different thickness single crystal shells have been prepared by using non-epitaxial growth method and cationic exchange method in water phase. The semiconductor CdS forms direct contact and clear interface on the surface of high curvature au nucleus nanocrystalline in three dimensional direction. Based on the local surface plasmon resonance (LSP) effect of precious metals, the LSPR enhanced high efficiency electron / hole separation and electron injection effect are generated under the excitation of incident photons. The properties of Au@CdS core-shell structure nanocrystals with different shell thickness were measured by photodissociation of water to produce hydrogen. The average hydrogen production rate of au / au nanocrystalline is as high as 24mmol h-1 g ~ (-1) when au nuclear size increases to about 35nm, which is more than 1000 times higher than that of CdS quantum dots of the same mass at the same time. The average hydrogen production rate of au ~ (35) nm CdS5nm nanocrystalline is 1000 times higher than that of CdS quantum dots of the same mass. In addition, under the action of LSPR effect, with the increase of CdS shell thickness, the LSPR on the surface of core-shell structure weakens gradually. With the aid of FDTD simulation, the principle of efficient photocatalytic hydrogen production with plasmon enhancement as the leading contribution is found. 2. The ability to supply transition metal ions 蟽 electrons with different phosphine ligands is different and the space steric hindrance of different phosphine ligands is different, which makes it more flexible to regulate the thermodynamics and kinetics of cationic exchange reactions. It has been found that cationic exchange reactions initiated by different phosphine ligands can be used to synthesize more precise semiconductor nanostructures, especially new metal / semiconductor core-shell nanocrystals and doped nanocrystallines. The morphology and related optical properties are more flexible to regulate. It has been found that compared with three Ding Ji phosphine, triphenylphosphine phosphine (PPh3), as a green reagent that can exist stably in air and has no irritant odor, can trigger cationic exchange reaction. The synthesis of Au@CdS and Pt@CdS nanostructures has good crystallinity and clear interface. The composition of au @ CdS1-xSex composite heterostructure and the high efficiency dopant luminescence regulation caused by heterovalent doping are also obtained.
【學位授予單位】：北京理工大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN304.2;TB383.1

【參考文獻】

相關期刊論文 前2條

1 周偉;張維;王程;趙子春;王延濤;牛文成;岳釗;劉國華;;貴金屬納米顆粒LSPR現(xiàn)象研究[J];傳感技術學報;2010年05期

2 李越湘,呂功煊,李樹本;半導體光催化分解水研究進展[J];分子催化;2001年01期

本文編號：1981787