这项工作与海军研究办公室颁发的海军部奖励 N00014-20-1-2858 和 N00014-22-1-2654 有关。表征在一定程度上得到了美国国家科学基金会主要研究仪器计划2216240资助的支持。这项工作也得到了马萨诸塞大学洛厄尔分校和马萨诸塞联邦的部分支持。我们感谢马萨诸塞大学洛厄尔分校的核心研究设施。

研究中使用的设备和试剂列在 材料表中。
1. 枸橼酸盐封端金纳米颗粒种子的Turkevich合成方法
<ol><li>玻璃器皿的清洁<ol><li>使用王水（HNO3:HCl的1:3摩尔比）清洁玻璃器皿和搅拌棒。</li>
		<li>用超纯水冲洗至无异味，并使用前晾干。</li>
	</ol></li>
	<li>试剂溶液的制备<ol><li>使用分析天平测量 39.4 mg HAuCl4∙3H2O 到干净且标记的 20 mL 玻璃闪烁瓶中。要制备 10 mM 溶液，将 10 mL 超纯水微量移液器加入溶液中。</li>
		<li>使用分析天平测量 58.8 mg 柠檬酸三钠二水合物，放入干净且标记的 20 mL 玻璃闪烁瓶中。要制备 100 mM 溶液，请将 10 mL 超纯水微量移液器放入溶液中。</li>
		<li>在使用前对两种前体溶液进行超声处理 30 秒;目视确认已发生总试剂溶解。</li>
	</ol></li>
	<li>金种子的合成<ol><li>将干净的 25.4 mm 聚四氟乙烯 （PTFE） 搅拌棒放入干净的 250 mL 圆底烧瓶中。</li>
		<li>向烧瓶中加入 58.56 mL 超纯水。</li>
		<li>将该烧瓶移至120 V 250 mL加热罩上，置于搅拌板上。</li>
		<li>组装加热罩并将连接的加热控制器设置为 138 °C，以 640 rpm 的速度搅拌。</li>
		<li>将冷凝器连接到圆底烧瓶的顶部，将其固定在支架上，然后将水流过冷凝器。</li>
		<li>当水在100°C下沸腾并且反应处于回流状态时，通过短暂移除冷凝器，直接将1.2mL的10mM HAuCl4 移液到溶液中。</li>
		<li>让反应返回回流，然后分离冷凝器。</li>
		<li>在单次添加中一次快速注射 480 μL 100 mM 柠檬酸三钠溶液。 注:100 mM 柠檬酸三钠应通过单次进样快速加入，以确保一致的单分散颗粒形成。</li>
		<li>立即将冷凝器放回烧瓶上，让溶液回流 8 分钟。 注意:柠檬酸盐注射约2分钟后，应观察到可见的颜色变为深紫红色，最终颜色为勃艮第。</li>
		<li>8分钟后，从加热罩中取出圆底烧瓶，使其恢复到室温。</li>
	</ol></li>
</ol>2. Au-Sn双金属纳米粒子的合成
<ol><li>前驱体溶液的制备<ol><li>要制备 10 wt% 聚乙烯吡咯烷酮 （PVP） 溶液，请执行以下步骤:<ol><li>使用分析天平准确测量 0.1 g PVP，放入干净且标记的 20 mL 玻璃闪烁瓶中。</li>
			<li>微量移液器将 1 mL 超纯水放入小瓶中。超声处理 1 分钟以完全溶解。</li>
		</ol></li>
		<li>要制备 5 mM SnCl4 溶液，请按照以下步骤操作:<ol><li>使用微量移液管，将 7.5 mL 超纯水转移到干净的 20 mL 闪烁瓶中。</li>
			<li>使用微量移液管将 4.34 μL SnCl4 快速注入小瓶中，并旋转溶液直至完全溶解。 注意:SnCl4 溶液应在通风橱中处理，因为它具有腐蚀性、烟雾和在环境条件下的反应性，可能导致试剂分解。</li>
		</ol></li>
		<li>要制备 260 mM NaBH4 溶液，请按照以下步骤操作:<ol><li>使用分析天平准确测量 20 mg NaBH4 到干净且标记的 20 mL 玻璃闪烁瓶中。 注:NaBH4 溶液在注入样品之前立即制备。</li>
		</ol></li>
	</ol></li>
	<li>双金属纳米粒子的形成<ol><li>将 6 mL 金种子和相应量的超纯水移液到带有 12.7 mm PTFE 搅拌棒的干净 20 mL 玻璃闪烁瓶中。 注:超纯水、PVP、SnCl4 和 NaBH4 的量取决于所制备的 %Au-Sn 溶液，可在 表 1 中找到。</li>
		<li>将小瓶放在搅拌板上，以 1,500 rpm 的速度开始搅拌。</li>
		<li>吸取适量的 10 wt% PVP 到反应瓶中。</li>
		<li>将相应量的 5 mM SnCl4 溶液加入反应瓶中。</li>
		<li>取出并盖紧反应瓶，放入60°C热水浴中10分钟。 注意:在此步骤中，搅拌棒可能会留在小瓶中。</li>
		<li>10分钟后，从热水浴中取出小瓶，打开盖子，然后以1,500rpm的速度将其放回搅拌板上。</li>
		<li>将 2.03 mL 超纯水加入含有固体 NaBH4 的小瓶中，盖紧盖子，摇匀直至溶解。</li>
		<li>立即将 260 mM NaBH4 溶液移液到反应瓶中，一次快速注射，并使其搅拌 30 秒。 注意:溶液的颜色从勃艮第变为黄橙色，并形成气泡。</li>
		<li>从搅拌板中取出反应瓶，松开盖子，并将其放入60°C热水浴中20分钟。</li>
		<li>20分钟后，将小瓶从热水浴中取出。</li>
		<li>从反应瓶中取出搅拌棒。</li>
		<li>在表征之前，让溶液冷却至室温。</li>
	</ol></li>
</ol>3. 等离子体双金属纳米粒子的光学表征
<ol><li>使用石英比色皿中的超纯水作为空白将仪器归零，并运行背景校正。</li>
	<li>将样品转移到路径长度为 1 cm 的干净石英比色皿中，以获得范围为 200-700 nm 的紫外-可见光谱。</li>
</ol>4. 等离子体双金属纳米粒子的结构表征
<ol><li>使用微量移液管将适量样品转移到 2.0 mL 微量离心管中，并在室温下以 5,510 x g 离心 8 分钟。</li>
	<li>8分钟后，使用移液管从管中取出上清液，而不干扰沉淀。颗粒留在管子的底部。</li>
	<li>向含有沉淀的试管中加入 1.50 mL 超纯水，涡旋重悬。</li>
	<li>再次以5,510× g 离心样品8分钟。</li>
	<li>完成后，除去大部分上清液，在每个试管中留下浓缩样品。应保留约 200 μL 浓缩颗粒胶体。</li>
	<li>使用移液器，将浓缩的样品转移到零背景硅支架上。</li>
	<li>将未覆盖的支架放入干燥器中完全干燥。</li>
	<li>干燥后，将样品放入 X 射线衍射仪中以收集数据。以波长为1.54 Å的Cu Kα 作为X射线源，在10°-90°的2θ范围内，扫描速率为1° min-1 。</li>
</ol>5. 等离子体双金属纳米粒子的成像
<ol><li>使用微量移液管将适量样品转移到 2.0 mL 微量离心管中，并以 5,510 x g 离心 8 分钟（室温下）。</li>
	<li>8分钟后，使用移液管从管中取出上清液，而不干扰沉淀。颗粒留在管子的底部。</li>
	<li>向含有沉淀的试管中加入 1.5 mL 超纯水，涡旋重悬。</li>
	<li>再次以5,510× g 离心样品8分钟。</li>
	<li>完成后，除去大部分上清液，并通过摇动样品手动搅拌管，直到沉淀均匀分散到剩余的上清液中。在每个试管中留下浓缩的样品。</li>
	<li>使用微量移液器，将 10 μL 浓缩样品移液到铜碳 B 型透射电子显微镜 （TEM） 网格上。</li>
	<li>将未覆盖的网格放入干燥器中约2小时晾干。 注:样品成像是使用具有 100 kV 加速电压的 TEM 进行的;使用 ImageJ 软件进行了多分散性和尺寸分析的附加分析。</li>
</ol>

等离子体金锡合金纳米颗粒的水合成

<ol><li>Fonseca Guzman, M. V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Plasmon+manipulation+by+post-transition+metal+alloying%5BTitle%5D)+AND+%22Matter%22%5BJournal%5D)">Plasmon manipulation by post-transition metal alloying.</a> Matter. 6 (3), 1-17 (2023).</li>
<li>Branco, A. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Synthesis+of+gold-tin+alloy+nanoparticles+with+tunable+plasmonic+properties%5BTitle%5D)+AND+%22STAR+Protoc%22%5BJournal%5D)">Synthesis of gold-tin alloy nanoparticles with tunable plasmonic properties.</a> STAR Protoc. 4 (3), 102410(2023).</li>
<li>Kelly, K. L., Coronado, E., Zhao, L. L., Schatz, G. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+optical+properties+of+metal+nanoparticles%3A+The+influence+of+size%2C+shape%2C+and+dielectric+environment%5BTitle%5D)+AND+%22J+Phys+Chem+B%22%5BJournal%5D)">The optical properties of metal nanoparticles: The influence of size, shape, and dielectric environment.</a> J Phys Chem B. 107 (3), 668-677 (2003).</li>
<li>Linic, S., Christopher, P., Xin, H., Marimuthu, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Catalytic+and+photocatalytic+transformations+on+metal+nanoparticles+with+targeted+geometric+and+plasmonic+properties%5BTitle%5D)+AND+%22Acc+Chem+Res%22%5BJournal%5D)">Catalytic and photocatalytic transformations on metal nanoparticles with targeted geometric and plasmonic properties.</a> Acc Chem Res. 46 (8), 1890-1899 (2013).</li>
<li>Naldoni, A., Shalaev, V. M., Brongersma, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Applying+plasmonics+to+a+sustainable+future%5BTitle%5D)+AND+%22Science%22%5BJournal%5D)">Applying plasmonics to a sustainable future.</a> Science. 356 (6341), 908-909 (2017).</li>
<li>King, M. E., Fonseca Guzman, M. V., Ross, M. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Material+strategies+for+function+enhancement+in+plasmonic+architectures%5BTitle%5D)+AND+%22Nanoscale%22%5BJournal%5D)">Material strategies for function enhancement in plasmonic architectures.</a> Nanoscale. 14 (3), 602-611 (2022).</li>
<li>Zhou, M., Li, C., Fang, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Noble-metal+based+random+alloy+and+intermetallic+nanocrystals%3A+Syntheses+and+applications%5BTitle%5D)+AND+%22Chem+Rev%22%5BJournal%5D)">Noble-metal based random alloy and intermetallic nanocrystals: Syntheses and applications.</a> Chem Rev. 121 (2), 736-795 (2020).</li>
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提交人声明没有竞争利益。

在这项研究中，使用Turkevich方法11制备了Au种子。关于该方法的程序局限性，有必要快速进行 480 μL 注射 100 mM 柠檬酸三钠。如果缓慢注入柠檬酸盐溶液，可能会形成具有大尺寸分布的多分散颗粒。此外，玻璃器皿的清洁度会显着影响金种子的质量和稠度。如果玻璃器皿在与王水一起使用之前没有很好地清洁，金种子就会聚集，如果紫色持续存在，可以目视观察到这一点。在表征?...

等离子体金属纳米粒子 1,2 在催化、光电子学、传感和可持续性方面具有应用，因为它们能够高效吸收光，将光集中到亚纳米体积中，并增强催化反应 3,4,5。只有少数金属表现出有效的局部表面等离子体共振（LSPRs）。其中，被广泛探索的金属之一是Au3。
金是一种被广泛研究的贵金属，以其与其他金属的稳定合金形成而闻名。然而，Au LSPR仅限于可见光和红外线，无法调谐到更高的能量6,7,8。同时，后过渡金属具有多种有趣的反应性和催化性，这与贵金属6,9,10不同。通过将金与后过渡金属合金化，LSPR可以向UV1的更高能量进行调整。该协议侧重于 Au-Sn 合金化。众所周知，Sn很容易与许多金属合金化，可以具有UV LSPRs，并且具有有趣的催化应用，例如通过二氧化碳还原形成甲酸6,7,8。Au 和 Sn 合金是通过化学还原和 Sn 扩散到晶种中来合成的。
该方法的主要目标是快速（即在几个小时内）合成水性金属纳米颗粒合金，并使用水化学在工作台上可重复地合成。最初，使用 Turkevich 方法11 制备 Au 晶种，然后进行基于晶种的扩散合成，这是形成无规合金纳米颗粒8 时的常用策略。值得注意的是，与其他需要更高温度、更高真空仪器或危险溶剂的方法 7,8 相比，Sn 的合金化在温和的环境中使用简单的设备需要相对较短的时间（~30 分钟）。该过程可以在温和的水性条件下进行，而无需繁重的环境控制。所得的Au-Sn合金具有一致的形貌、尺寸、形状和光学性能，可以通过控制Sn含量来控制。

<table><tbody><tr><td>Basix Microcentrifuge Tubes</td><td>Fisher Scientific</td><td>Cat#02-682-004</td><td></td></tr><tr><td>Cary 100 UV-visible Spectrophotometer</td><td>Agilent Technologies</td><td>Cat#G9821A; RRID:SCR_019481</td><td></td></tr><tr><td>Cary WinUV</td><td>Agilent Technologies</td><td></td><td>https://www.agilent.com/en/product/molecular-spectroscopy/uv-vis-uv-visnir-spectroscopy/uv-vis-uv-vis-nirsoftware/cary-winuv-softwar</td></tr><tr><td>Crystallography Open Database</td><td>CrystalEye</td><td>RRID: SCR_005874</td><td>http://www.crystallography.net/</td></tr><tr><td>Cu Carbon Type-B Grids&lt;br/&gt; (200 mesh, 97 &amp;micro;m grid holes)</td><td>Ted Pella</td><td>Cat#01811</td><td></td></tr><tr><td>Direct-Q 3 UV-R Water Purification System</td><td>MilliporeSigma</td><td>Cat#ZRQSVR300</td><td></td></tr><tr><td>Entris Analytical Balance</td><td>Sartorius</td><td>Cat#ENTRIS64I-1SUS</td><td></td></tr><tr><td>Glass round-bottom flask (250 mL)</td><td>Fisher Scientific</td><td>Cat#FB201250</td><td></td></tr><tr><td>Glass scintillation vials</td><td>Wheaton</td><td>Cat#986548</td><td></td></tr><tr><td>Hydrochloric acid&lt;br/&gt; (HCl, NF/FCC)</td><td>Fisher Scientific</td><td>CAS: 7647-01-0, 7732-18-5</td><td></td></tr><tr><td>Hydrogen tetrachloroaurate (III) trihydrate&lt;br/&gt; (HAuCl&lt;sub&gt;4&lt;/sub&gt;&amp;middot;3H&lt;sub&gt;2&lt;/sub&gt;O, 99.99%)</td><td>Alfa Aesar</td><td>CAS: 16961-25-4</td><td>kept in a desiccator for consistency of purity and stability</td></tr><tr><td>ImageJ</td><td>National Institute of Health</td><td>RRID: SCR_003070</td><td>https://imagej.nih.gov/ij/download.html</td></tr><tr><td>Isotemp GPD 10 Hot Water Bath</td><td>Fisher Scientific</td><td>Cat#FSGPD10</td><td></td></tr><tr><td>Isotemp Hot Plate Stirrer</td><td>Fisher Scientific</td><td>Cat#SP88857200</td><td></td></tr><tr><td>Mili-Q Ultrapure Water&lt;br/&gt; (18.2 M&amp;Omega;-cm)</td><td>Water purification system</td><td></td><td></td></tr><tr><td>Miniflex X-Ray Diffractometer</td><td>Rigaku</td><td>RRID:SCR_020451</td><td>https://www.rigaku.com/products/xrd/miniflex</td></tr><tr><td>Model 5418 Microcentrifuge</td><td>Eppendorf</td><td>Cat#022620304</td><td></td></tr><tr><td>Nitric acid&lt;br/&gt; (HNO&lt;sub&gt;3&lt;/sub&gt;, Certified ACS Plus)</td><td>Fisher Scientific</td><td>CAS: 7697-37-2, 7732-18-5</td><td></td></tr><tr><td>On/Off Temperature Controller for Heating Mantle</td><td>Fisher Scientific</td><td>Cat#11476289</td><td></td></tr><tr><td>Optifit Racked Pipette Tips (0.5-200 &amp;micro;L)</td><td>Sartorius</td><td>Cat#790200</td><td></td></tr><tr><td>Optifit Racked Pipette Tips (10-1000 &amp;micro;L)</td><td>Sartorius</td><td>Cat#791000</td><td></td></tr><tr><td>Philips CM12 120 kV Transmission Electron Microscope</td><td>Philips</td><td>RRID:SCR_020411</td><td></td></tr><tr><td>Pipette Tups (1-10 mL)</td><td>USA Scientific</td><td>Cat#1051-0000</td><td></td></tr><tr><td>Poly(vinylpyrrolidone)&lt;br/&gt; (PVP; molecular weight [MW] = 40,000)</td><td>Alfa Aesar</td><td>CAS: 9003-39-8</td><td>kept in a desiccator for consistency of purity and stability</td></tr><tr><td>Practum Precision Balance</td><td>Sartorius</td><td>Cat# PRACTUM1102-1S</td><td></td></tr><tr><td>PTFE Magnetic Stir Bar (12.7 mm)</td><td>Fisher Scientific</td><td>Cat#14-513-93</td><td></td></tr><tr><td>PTFE Magnetic Stir Bar (25.4 mm)</td><td>Fisher Scientific</td><td>Cat#14-513-94</td><td></td></tr><tr><td>Quartz Cuvette&lt;br/&gt; (length &amp;times; width &amp;times; height: 10 mm &amp;times; 12.5 mm &amp;times; 45 mm)</td><td>Fisher Scientific</td><td>Cat#14-958-126</td><td></td></tr><tr><td>Round Bottom Heating Mantle 120 V 250 mL</td><td>Fisher Scientific</td><td>Cat#11-476-004</td><td></td></tr><tr><td>SmartLab Studio II</td><td>Rigaku</td><td></td><td>https://www.rigaku.com/products/xrd/studio</td></tr><tr><td>Sodium borohydride&lt;br/&gt; (NaBH&lt;sub&gt;4&lt;/sub&gt;, 97+%)</td><td>Alfa Aesar</td><td>CAS: 16940-66-2</td><td>kept in a desiccator for consistency of purity and stability</td></tr><tr><td>SureOne Pipette Tips (0.1-10 &amp;micro;L)</td><td>Fisher Scientific</td><td>Cat#02-707-437</td><td></td></tr><tr><td>Tacta Mechanical Pipette (P10)</td><td>Sartorius</td><td>Cat#LH-729020</td><td></td></tr><tr><td>Tacta Mechanical Pipette (P1000)</td><td>Sartorius</td><td>Cat#LH-729070</td><td></td></tr><tr><td>Tacta Mechanical Pipette (P10000)</td><td>Sartorius</td><td>Cat#LH-729090</td><td></td></tr><tr><td>Tacta Mechanical Pipette (P20)</td><td>Sartorius</td><td>Cat#LH-729030</td><td></td></tr><tr><td>Tacta Mechanical Pipette (P200)</td><td>Sartorius</td><td>Cat#LH-729060</td><td></td></tr><tr><td>Tin (IV) chloride&lt;br/&gt; (SnCl&lt;sub&gt;4&lt;/sub&gt;, 99.99%)</td><td>Alfa Aesar</td><td>CAS: 7646-78-8</td><td>kept in the fume hood and sealed with Parafilm between uses to avoid exposure to ambient conditions</td></tr><tr><td>Trisodium citrate dihydrate&lt;br/&gt; (C&lt;sub&gt;6&lt;/sub&gt;H&lt;sub&gt;5&lt;/sub&gt;Na&lt;sub&gt;3&lt;/sub&gt;O&lt;sub&gt;7&lt;/sub&gt;&amp;middot;2H&lt;sub&gt;2&lt;/sub&gt;O, 99%)</td><td>Alfa Aesar</td><td>CAS: 6132-04-3</td><td>kept in a desiccator for consistency of purity and stability</td></tr><tr><td>Zero-Background Si Sample Holder</td><td>Rigaku</td><td></td><td></td></tr></tbody></table>

aqueous synthesis of plasmonic gold-tin alloy nanoparticles

该协议描述了Au纳米颗粒种子的合成以及随后形成的Au-Sn双金属纳米颗粒。这些纳米颗粒在催化、光电子学、成像和药物输送方面具有潜在的应用。以前，生产合金纳米颗粒的方法非常耗时，需要复杂的反应条件，并且可能产生不一致的结果。概述的协议首先描述了使用Turkevich方法合成约13nm Au纳米颗粒种子。该协议接下来描述了Sn的还原及其掺入Au种子中以生成Au-Sn合金纳米颗粒。描述了这些纳米颗粒的光学和结构表征。从光学角度来看，使用紫外-可见光谱法可以明显地看到突出的局部表面等离子体共振（LSPRs）。在结构上，粉末 X 射线衍射 （XRD） 反射所有小于 20 nm 的颗粒，并显示 Au、Sn 和多个 Au-Sn 金属间相的图案。通过透射电子显微镜（TEM）成像获得球形貌和尺寸分布。透射电镜显示，在Sn掺入后，纳米颗粒的直径增长到约15 nm。

图1 显示了Au种子和Au-Sn合金纳米颗粒的代表性结果。按照金种子合成方案，在517 nm附近观察到一个明显的不对称吸收峰，消光最大值约为0.7，对应于LSPR。峰值蓝色随着 Sn 的加入而移动，与样品中明显的光学颜色变化相关，从勃艮第色到橙色再到棕褐色。随着 Sn 添加百分比的增加，观察到峰的进一步蓝移和加宽。如果添加 10%、20%、30% 和 40% Sn，预期的 LSPR 最大值约为 514 nm、...

Read this Scientific Article Protocol about Author Spotlight: Designing Sustainable Nanomaterials for Advancing Synthesis and Element Mixing at JoVE.com

作者聚焦:设计可持续的纳米材料以促进合成和元素混合

在这里，使用 Turkevich 方法描述了金 （Au） 种子的合成。然后，这些种子用于合成具有可调等离子体特性的金锡合金（Au-Sn）纳米颗粒。

This protocol describes the synthesis of Au nanoparticle seeds and the subsequent formation of Au-Sn bimetallic nanoparticles. These nanoparticles have ...

我们的研究重点是设计和创造新型纳米材料，这些纳米材料结合了影响可持续性和能源方面重大挑战的各种元素。这项工作的一个主要重点是了解如何在元素周期表中混合具有不同属性的元素。大多数合金金属纳米颗粒的合成都需要高温、有机溶剂，并且我们需要去除氧气。我们的合成产品在温和的条件下，在水中，并在温和的加热下在工作台上工作。我们未来的研究将侧重于探索这种策略的普遍性，将多种元素整合到合金纳米颗粒中，同时控制它们的大小和形状。这些对于解锁新属性至关重要。

aqueous-synthesis-of-plasmonic-gold-tin-alloy-nanoparticles

Research

JoVE Journal

Chemistry

Aqueous Synthesis of Plasmonic Gold-Tin Alloy Nanoparticles

907 次观看.  University of Massachusetts Lowell. 我们的研究重点是设计和创造新型纳米材料，这些纳米材料结合了影响可持续性和能源方面重大挑战的各种元素。这项工作的一个主要重点是了解如何在元素周期表中混合具有不同属性的元素。大多数合金金属纳米颗粒的合成都需要高温、有机溶剂，并且我们需要去除氧气。我们的合成产品在温和的条件下，在水中，并在温和的加热下在工作台上工作。我们未来的研究?...

视频: 作者聚焦:设计可持续的纳米材料以促进合成和元素混合

Template Directed Synthesis of Plasmonic Gold Nanotubes with Tunable IR Absorbance

A nearly parallel array of pores can be produced by anodizing aluminum foils in acidic environments1, 2. Applications of anodic aluminum oxide (AAO) membranes have been under development since the 1990's and have become a common method to template the synthesis of high aspect ratio nanostructures, mostly by electrochemical growth or pore-wetting. Recently, these membranes have become commercially available in a wide range of pore sizes and densities, leading to an extensive library of functional nanostructures being synthesized from AAO membranes. These include composite nanorods, nanowires and nanotubes made of metals, inorganic materials or polymers 3-10. Nanoporous membranes have been used to synthesize nanoparticle and nanotube arrays that perform well as refractive index sensors, plasmonic biosensors, or surface enhanced Raman spectroscopy (SERS) substrates 11-16, as well as a wide range of other fields such as photo-thermal heating 17, permselective transport 18, 19, catalysis 20, microfluidics 21, and electrochemical sensing 22, 23. Here, we report a novel procedure to prepare gold nanotubes in AAO membranes. Hollow nanostructures have potential application in plasmonic and SERS sensing, and we anticipate these gold nanotubes will allow for high sensitivity and strong plasmon signals, arising from decreased material dampening 15.

Solution-suspendable gold nanotubes with controlled dimensions can be synthesized by electrochemical deposition in porous anodic aluminum oxide (AAO) membranes using a hydrophobic polymer core. Gold nanotubes and nanotube arrays hold promise for applications in plasmonic biosensing, surface-enhanced Raman spectroscopy, photo-thermal heating, ionic and molecular transport, microfluidics, catalysis and electrochemical sensing.

的模板导演电浆黄金纳米管的合成与可调谐红外吸收

A nearly parallel array of pores can be produced by anodizing aluminum foils in acidic environments1, 2. Applications of anodic aluminum oxide (AAO) ...

科研

化学

Synthesis and Catalytic Performance of Gold Intercalated in the Walls of Mesoporous Silica

As a promising catalytically active nano reactor, gold nanoparticles intercalated in mesoporous silica (GMS) were successfully synthesized and properties of the materials were investigated. We used a one pot sol-gel approach to intercalate gold nano particles in the walls of mesoporous silica. To start with the synthesis, P123 was used as template to form micelles. Then TESPTS was used as a surface modification agent to intercalate gold nano particles. Following this process, TEOS was added in as a silica source which underwent a polymerization process in acid environment. After hydrothermal processing and calcination, the final product was acquired. Several techniques were utilized to characterize the porosity, morphology and structure of the gold intercalated mesoporous silica. The results showed a stable structure of mesoporous silica after gold intercalation. Through the oxidation of benzyl alcohol as a benchmark reaction, the GMS materials showed high selectivity and recyclability.

Here, we present a protocol with a sol-gel process to synthesize gold intercalated in the walls of mesoporous materials (GMS), which is confirmed to possess a mesoporous matrix with gold intercalated in the walls imparting great stability and recyclability.

合成和金插在介孔二氧化硅的墙壁催化性能

As a promising catalytically active nano reactor, gold nanoparticles intercalated in mesoporous silica (GMS) were successfully synthesized and properties ...

Synthesis, Characterization, and Functionalization of Hybrid Au/CdS and Au/ZnS Core/Shell Nanoparticles

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large extinction coefficients which can be tuned across the visible spectrum. Research into the plasmonic enhancement of optical transitions has become popular, due to the possibility of altering and in some cases improving photo-absorption or emission properties of nearby chromophores such as molecular dyes or quantum dots. The electric field of the plasmon can couple with the excitation dipole of a chromophore, perturbing the electronic states involved in the transition and leading to increased absorption and emission rates. These enhancements can also be negated at close distances by energy transfer mechanism, making the spatial arrangement of the two species critical. Ultimately, enhancement of light harvesting efficiency in plasmonic solar cells could lead to thinner and, therefore, lower cost devices. The development of hybrid core/shell particles could offer a solution to this issue. The addition of a dielectric spacer between a gold nanoparticles and a chromophore is the proposed method to control the exciton plasmon coupling strength and thereby balance losses with the plasmonic gains. A detailed procedure for the coating of gold nanoparticles with CdS and ZnS semiconductor shells is presented. The nanoparticles show high uniformity with size control in both the core gold particles and shell species allowing for a more accurate investigation into the plasmonic enhancement of external chromophores.

The synthesis of uniform gold nanoparticles coated with semiconductor shells of CdS or ZnS is performed. The semiconductor coating is conducted by first depositing a silver sulfide shell and exchanging the silver cations for zinc or cadmium cations.

合成，表征和混合金/硫化镉和Au / ZnS核/壳纳米颗粒功能化

Plasmonic nanoparticles are an attractive material for light harvesting applications due to their easily modified surface, high surface area and large ...

Multifunctional Hybrid Fe2O3-Au Nanoparticles for Efficient Plasmonic Heating

One of the most widely used methods for manufacturing colloidal gold nanospherical particles involves the reduction of chloroauric acid (HAuCl4) to neutral gold Au(0) by reducing agents, such as sodium citrate or sodium borohydride. The extension of this method to decorate iron oxide or similar nanoparticles with gold nanoparticles to create multifunctional hybrid Fe2O3-Au nanoparticles is straightforward. This approach yields fairly good control over Au nanoparticle dimensions and loading onto Fe2O3. Additionally, the Au metal size, shape, and loading can easily be tuned by changing experimental parameters (e.g., reactant concentrations, reducing agents, surfactants, etc.). An advantage of this procedure is that the reaction can be done in air or water, and, in principle, is amenable to scaling up. The use of such optically tunable Fe2O3-Au nanoparticles for hyperthermia studies is an attractive option as it capitalizes on plasmonic heating of gold nanoparticles tuned to absorb light strongly in the VIS-NIR region. In addition to its plasmonic effects, nanoscale Au provides a unique surface for interesting chemistries and catalysis. The Fe2O3 material provides additional functionality due to its magnetic property. For example, an external magnetic field could be used to collect and recycle the hybrid Fe2O3-Au nanoparticles after a catalytic experiment, or alternatively, the magnetic Fe2O3 can be used for hyperthermia studies through magnetic heat induction. The photothermal experiment described in this report measures bulk temperature change and nanoparticle solution mass loss as functions of time using infrared thermocouples and a balance, respectively. The ease of sample preparation and the use of readily available equipment are distinct advantages of this technique. A caveat is that these photothermal measurements assess the bulk solution temperature and not the surface of the nanoparticle where the heat is transduced and the temperature is likely to be higher.

Multifunctional Hybrid Fe2O3-Au Nanoparticles for Efficient Plasmonic Heating

We describe the synthesis and properties of multifunctional Fe2O3-Au nanoparticles produced by a wet chemical approach and investigate their photothermal properties using laser irradiation. The composite Fe2O3-Au nanoparticles retain the properties of both materials, creating a multifunctional structure with excellent magnetic and plasmonic properties.

多功能混合铁<sub&gt; 2</sub&gt; 0<sub&gt; 3</sub&gt; -Au纳米粒子高效的电浆暖气

One of the most widely used methods for manufacturing colloidal gold nanospherical particles involves the reduction of chloroauric acid (HAuCl4) to ...

工程学

Colloidal Synthesis of Nanopatch Antennas for Applications in Plasmonics and Nanophotonics

We present a method for colloidal synthesis of silver nanocubes and the use of these in combination with a smooth gold film, to fabricate plasmonic nanoscale patch antennas. This includes a detailed procedure for the fabrication of thin films with a well-controlled thickness over macroscopic areas using layer-by-layer deposition of polyelectrolyte polymers, namely poly(allylamine) hydrochloride (PAH) and polystyrene sulfonate (PSS). These polyelectrolyte spacer layers serve as a dielectric gap in between silver nanocubes and a gold film. By controlling the size of the nanocubes or the gap thickness, the plasmon resonance can be tuned from about 500 nm to 700 nm. Next, we demonstrate how to incorporate organic sulfo-cyanine5 carboxylic acid (Cy5) dye molecules into the dielectric polymer gap region of the nanopatch antennas. Finally, we show greatly enhanced fluorescence of the Cy5 dyes by spectrally matching the plasmon resonance with the excitation energy and the Cy5 absorption peak. The method presented here enables the fabrication of plasmonic nanopatch antennas with well-controlled dimensions utilizing colloidal synthesis and a layer-by-layer dip-coating process with the potential for low cost and large-scale production. These nanopatch antennas hold great promise for practical applications, for example in sensing, ultrafast optoelectronic devices and for high-efficiency photodetectors.

A protocol for the colloidal synthesis of silver nanocubes and fabrication of plasmonic nanoscale patch antennas with sub-10 nm gaps is presented.

在等离子体激元和纳米光子学应用Nanopatch天线的合成胶体

We present a method for colloidal synthesis of silver nanocubes and the use of these in combination with a smooth gold film, to fabricate plasmonic ...

In Situ Synthesis of Gold Nanoparticles without Aggregation in the Interlayer Space of Layered Titanate Transparent Films

Combinations of metal oxide semiconductors and gold nanoparticles (AuNPs) have been investigated as new types of materials. The in situ synthesis of AuNPs within the interlayer space of semiconducting layered titania nanosheet (TNS) films was investigated here. Two types of intermediate films (i.e., TNS films containing methyl viologen (TNS/MV2+) and 2-ammoniumethanethiol (TNS/2-AET+)) were prepared. The two intermediate films were soaked in an aqueous tetrachloroauric(III) acid (HAuCl4) solution, whereby considerable amounts of Au(III) species were accommodated within the interlayer spaces of the TNS films. The two types of obtained films were then soaked in an aqueous sodium tetrahydroborate (NaBH4) solution, whereupon the color of the films immediately changed from colorless to purple, suggesting the formation of AuNPs within the TNS interlayer. When only TNS/MV2+ was used as the intermediate film, the color of the film gradually changed from metallic purple to dusty purple within 30 min, suggesting that aggregation of AuNPs had occurred. In contrast, this color change was suppressed by using the TNS/2-AET+ intermediate film, and the AuNPs were stabilized for over 4 months, as evidenced by the characteristic extinction (absorption and scattering) band from the AuNPs.

In Situ Synthesis of Gold Nanoparticles without Aggregation in the Interlayer Space of Layered Titanate Transparent Films

Here, we present a protocol for the in situ synthesis of gold nanoparticles (AuNPs) within the interlayer space of layered titanate films without the aggregation of AuNPs. No spectral change was observed even after 4 months. The synthesized material has expected applications in catalysis, photo-catalysis, and the development of cost-effective plasmonic devices.

在没有聚集的层状钛酸盐薄膜透明的层间金纳米粒子的原位合成

Combinations of metal oxide semiconductors and gold nanoparticles (AuNPs) have been investigated as new types of materials. The in situ synthesis of AuNPs ...

Fabrication of Periodic Gold Nanocup Arrays Using Colloidal Lithography

Within recent years, the field of plasmonics has exploded as researchers have demonstrated exciting applications related to chemical and optical sensing in combination with new nanofabrication techniques. A plasmon is a quantum of charge density oscillation that lends nanoscale metals such as gold and silver unique optical properties. In particular, gold and silver nanoparticles exhibit localized surface plasmon resonances-collective charge density oscillations on the surface of the nanoparticle-in the visible spectrum. Here, we focus on the fabrication of periodic arrays of anisotropic plasmonic nanostructures. These half-shell (or nanocup) structures can exhibit additional unique light-bending and polarization-dependent optical properties that simple isotropic nanostructures cannot. Researchers are interested in the fabrication of periodic arrays of nanocups for a wide variety of applications such as low-cost optical devices, surface-enhanced Raman scattering, and tamper indication. We present a scalable technique based on colloidal lithography in which it is possible to easily fabricate large periodic arrays of nanocups using spin-coating and self-assembled commercially available polymeric nanospheres. Electron microscopy and optical spectroscopy from the visible to near-infrared (near-IR) was performed to confirm successful nanocup fabrication. We conclude with a demonstration of the transfer of nanocups to a flexible, conformal adhesive film.

We demonstrate the fabrication of periodic gold nanocup arrays using colloidal lithographic techniques and discuss the importance of nanoplasmonic films.

用胶体光刻制备周期性金 Nanocup 阵列

Within recent years, the field of plasmonics has exploded as researchers have demonstrated exciting applications related to chemical and optical sensing ...

Photodeposition of Pd onto Colloidal Au Nanorods by Surface Plasmon Excitation

A protocol is described to photocatalytically guide Pd deposition onto Au nanorods (AuNR) using surface plasmon resonance (SPR). Excited plasmonic hot electrons upon SPR irradiation drive reductive deposition of Pd on colloidal AuNR in the presence of [PdCl4]2-. Plasmon-driven reduction of secondary metals potentiates covalent, sub-wavelength deposition at targeted locations coinciding with electric field &#8220;hot-spots&#8221; of the plasmonic substrate using an external field (e.g., laser). The process described herein details a solution-phase deposition of a catalytically-active noble metal (Pd) from a transition metal halide salt (H2PdCl4) onto aqueously-suspended, anisotropic plasmonic structures (AuNR). The solution-phase process is amenable to making other bimetallic architectures. Transmission UV-vis monitoring of the photochemical reaction, coupled with ex situ XPS and statistical TEM analysis, provide immediate experimental feedback to evaluate properties of the bimetallic structures as they evolve during the photocatalytic reaction. Resonant plasmon irradiation of AuNR in the presence of [PdCl4]2- creates a thin, covalently-bound Pd0 shell without any significant dampening effect on its plasmonic behavior in this representative experiment/batch. Overall, plasmonic photodeposition offers an alternative route for high-volume, economical synthesis of optoelectronic materials with sub-5 nm features (e.g., heterometallic photocatalysts or optoelectronic interconnects).

A protocol for anisotropic photodeposition of Pd onto aqueously-suspended Au nanorods via localized surface plasmon excitation is presented.

通过表面等离子体激发将 Pd 光沉积到胶体 Au 纳米棒上

A protocol is described to photocatalytically guide Pd deposition onto Au nanorods (AuNR) using surface plasmon resonance (SPR). Excited plasmonic hot ...

Preparation of Silver-Palladium Alloyed Nanoparticles for Plasmonic Catalysis under Visible-Light Illumination

Localized surface plasmon resonance (LSPR) in plasmonic nanoparticles (NPs) can accelerate and control the selectivity of a variety of molecular transformations. This opens possibilities for the use of visible or near-IR light as a sustainable input to drive and control reactions when plasmonic nanoparticles supporting LSPR excitation in these ranges are employed as catalysts. Unfortunately, this is not the case for several catalytic metals such as palladium (Pd). One strategy to overcome this limitation is to employ bimetallic NPs containing plasmonic and catalytic metals. In this case, the LSPR excitation in the plasmonic metal can contribute to accelerate and control transformations driven by the catalytic component. The method reported herein focuses on the synthesis of bimetallic silver-palladium (Ag-Pd) NPs supported on ZrO2 (Ag-Pd/ZrO2) that acts as a plasmonic-catalytic system. The NPs were prepared by co-impregnation of corresponding metal precursors on the ZrO2 support followed by simultaneous reduction leading to the formation of bimetallic NPs directly on the ZrO2 support. The Ag-Pd/ZrO2 NPs were then used as plasmonic catalysts for the reduction of nitrobenzene under 425 nm illumination by LED lamps. Using gas chromatography (GC), the conversion and selectivity of the reduction reaction under the dark and light irradiation conditions can be monitored, demonstrating the enhanced catalytic performance and control over selectivity under LSPR excitation after alloying non-plasmonic Pd with plasmonic metal Ag. This technique can be adapted to a wide range of molecular transformations and NPs compositions, making it useful for the characterization of the plasmonic catalytic activity of different types of catalysis in terms of conversion and selectivity.

Presented here is a protocol for the synthesis of silver-palladium (Ag-Pd) alloy nanoparticles (NPs) supported on ZrO2 (Ag-Pd/ZrO2). This system allows for harvesting energy from visible light irradiation to accelerate and control molecular transformations. This is illustrated by nitrobenzene reduction under light irradiation catalyzed by Ag-Pd/ZrO2 NPs.

在可见光照射下为质子催化准备银-铂合金纳米粒子

Localized surface plasmon resonance (LSPR) in plasmonic nanoparticles (NPs) can accelerate and control the selectivity of a variety of molecular ...

Gold Nanoparticle Synthesis

Gold nanoparticles (Au nanoparticles) that are ~12 nm in diameter were synthesized by rapidly injecting a solution of 150 mg (0.15 mmol) of tetrachloroauric acid in 3.0 g (3.7 mmol, 3.6 mL) of oleylamine (technical grade) and 3.0 mL of toluene into a boiling solution of 5.1 g (6.4 mmol, 8.7 mL) of oleylamine in 147 mL of toluene. While boiling and mixing the reaction solution for 2 hours, the color of the reaction mixture changed from clear, to light yellow, to light pink, and then slowly to dark red. The heat was then turned off, and the solution was allowed to gradually cool down to room temperature for 1 hour. The gold nanoparticles were then collected and separated from the solution using a centrifuge and washed three times; by vortexing and dispersing the gold nanoparticles in 10 mL portions of toluene, and then precipitating the gold nanoparticles by adding 40 mL portions of methanol and spinning them in a centrifuge. The solution was then decanted to remove any remaining byproducts and unreacted starting materials. Drying the gold nanoparticles in a vacuum environment produced a solid black pellet; which could be stored for long periods of time (up to one year) for later use, and then redissolved in organic solvents such as toluene.

A protocol for synthesizing ~12 nm diameter gold nanoparticles (Au nanoparticles) in an organic solvent is presented. The gold nanoparticles are capped with oleylamine ligands to prevent agglomeration. The gold nanoparticles are soluble in organic solvents such as toluene.