荷兰科学研究组织（NWO-CW）的TOP计划的框架内的化学科学部的财政支持是公认的。

分段银| ZnO纳米线形成的PCTE膜 1。PCTE膜的制备为模板电<ol><li>选择一个轨道蚀刻聚碳酸酯膜的200nm的外孔直径和厚度为6μm（ 图2a）中。这里所用的膜的直径为25毫米。 </li><li>溅射的金层在膜（ 图2b）的背面。在这种情况下，为2×10 -2毫巴的沉积压力，使用用Ar作为溅射气体。用〜13纳米/分钟缓慢的沉积速率。注：电沉积期间该Au层将用作电接触。 </li><li>使用双面胶带附加一个小的载玻片（1.4×2.1公分）上的膜的涂覆金的一侧的顶部。对于这一点，把双面胶带四个小条沿载玻片（ 图2c）的边缘。注意：请确保膜是尽可能顺利，没有任何褶皱。此载玻片是用来确保膜孔内部选择性电镀。 </li><li>贴一小块铜带上，伸出距离为机械稳定性载玻片，膜的一部分。因为铜带导通时，在工作电极的鳄鱼夹可以连接到铜带。 </li><li>如果需要，通过将Teflon带周围的边缘提高膜的粘合性的玻璃载玻片。注：对于沉积在室温下的双面胶带的粘合通常是足够强的，但在高温下它是推荐使用特氟龙胶带为好。 </li></ol> 。银2电| ZnO纳米线<ol><li>银段的制备<ol><li>制备含0.20摩尔AgNO 3（每50ml1.70克）和0.10 MH 3 BO 3（每50ml0.31克）的水溶液。用HNO 3调节pH值至1.5。 </li><li>把准备膜一起用Pt对电极和在所制备的溶液中的Ag / AgCl（3M KCl）中的参比电极。 </li><li>适用的0.10伏的电位与30秒对于Ag / AgCl参比电极（ 图2d和2e）。注意：虽然每个恒电位仪软件会有所不同，所有的程序应该有一个像“设置潜在的”输入线和“持续时间”，而这些数值可以填写。请参考电位手动和附带的软件的更多细节。 </li><li>就拿电极从溶液中，并用Milli-Q水冲洗。 </li></ol></li><li>氧化锌段的制备<ol><li>制备含0.10M的锌（NO 3）2·6H 2 O（1.49克每50ml）的水溶液。 </li><li>加热该溶液至60℃，使用水浴，然后将载有银段一起用Pt对电极和在该加热的溶液中的Ag / AgCl参比电极的膜。 </li><li&gt;应用为-1.00 V，相对于20分钟的银/氯化银参比电极的电位（ 图2d和2e）。注意：虽然每个恒电位仪程序会有所不同，都应该有一个像“设置潜在的”输入线和“持续时间”，而这些数值可以填写。请参考电位手动和附带的软件的更多细节。 </li><li>就拿电极从溶液中，并用Milli-Q水冲洗。 </li></ol></li><li>重复此步骤4倍，获得足够的纳米线的显著信号从H 2传感器。 </li></ol>该纳米线的3。提取和转移到水溶液<ol><li>切含有来自载玻片上的纳米线膜。 </li><li>这部分的膜转移到聚丙烯离心管中。 </li><li>添加约2ml 的 CH 2 Cl 2中以溶解PCTE膜并释放纳米线到溶液中。后〜30分钟后，将膜应完全溶解（ 图2F和2G）。 </li><li>取一小滴含有一个小硅片上纳米线的SEM分析的二氯甲烷溶液中。 </li><li>离心所得到的在〜19,000×g离心溶液5分钟，除去过量的CH 2 Cl 2中 ，并添加新鲜的CH 2 Cl 2。重复上述过程，至少3倍，以确保所有的聚碳酸酯已被删除。 </li><li>毕竟聚碳酸酯已被去除，去除过量的CH 2 Cl 2后，milli-Q水中添加到纳米线。至少3倍再次重复离心完全取代所有的CH 2 Cl 2中通过的Milli-Q水。 </li></ol>同轴的TiO 2银纳米线形成的氧化铝膜 4，阳极氧化铝膜的制备为模板电<ol><li>采取AAO膜具有200nm和60微米厚的孔径（ <sTRONG&gt;图2a）。这里所用的膜的直径为13毫米。 </li><li>溅射的金层上的膜（ 图2b）的背面。在这种情况下为2×10 -2毫巴的沉积压力，使用用Ar作为溅射气体。用〜13纳米/分钟缓慢的沉积速率。注：电沉积期间该Au层将用作电接触。 </li><li>附加的氧化铝膜，以在配置在图2h用特氟龙胶带的Au涂层的载玻片上。注：为了确保膜毛孔内选择性电镀，阳极氧化铝膜需要被附加到一个不同的配置比PCTE膜的小玻璃片上，因为阳极氧化铝膜是太脆与鳄鱼夹连接。时的3.0×2.5厘米的玻璃载片使用时，两种膜可用于一次。 </li><li>把一小块铜带上，易于处理的玻片上的金涂层的部分连接时，电DES。 </li></ol> 5，电化学TiO 2的银纳米线沉积<ol><li>一TiO 2的凝胶的制备<ol><li>制备含有0.02M的TiOSO 4（每50ml0.16克）的水溶液0.03 MH 2 O 2（每50ml0.13毫升），0.05M的HNO 3（每50ml0.15毫升）和0.25M的KNO 3（1.26克每50ml）中。 </li><li>把所制备的膜一起用Pt对电极和在所制备的溶液中的Ag / AgCl（3M KCl）中的参比电极。 </li><li>适用的-1.0 V与3.5小时的Ag / AgCl参考电极的电位（ 图2d和2e）。注意：虽然每个恒电位仪软件会有所不同，所有的程序应该有一个像“设置潜在的”输入线和“持续时间”，而这些数值可以填写。请参考电位手动和附带的软件的更多细节。 </li><li>就拿电极从溶液中和不要冲洗该膜用milli-Q水中，由于TiO 2的凝胶仍然是水溶性的。其它电极可冲洗milli-Q水中。 </li></ol></li><li>同轴二氧化钛-银纳米线的制备<ol><li>热退火用的TiO 2凝胶膜在烘箱中于650℃进行2小时的空气。 </li><li>重新将膜的黄金镀膜玻璃幻灯片。 </li><li>制备含0.20摩尔AgNO 3（每50ml1.70克）和0.10 MH 3 BO 3（每50ml0.31克）的水溶液。用HNO 3调节pH值至1.5。 </li><li>把所制备的膜一起用Pt对电极和在所制备的溶液中的Ag / AgCl（3M KCl）中的参比电极。 </li><li>适用的0.10伏的电位与1.5分钟对于Ag / AgCl参比电极（ 图2d和2e）。注意：虽然每个恒电位仪软件会有所不同，所有的程序应该有一个像“设置POTE输入线微分方程边值问题的“和”持续时间“，而这些数值可以填写请参考电位手动和附带的软件的更多细节。 </li><li>就拿电极从溶液中，并用Milli-Q水冲洗。 </li></ol></li><li>在TiO 2纳米管掺入银纳米粒子的制备<ol><li>加热与TiO 2的凝胶过夜，膜在100℃下</li><li>制备含0.20摩尔AgNO 3（每50ml1.70克）和0.10 MH 3 BO 3（每50ml0.31克）的水溶液。用HNO 3调节pH值至1.5。 </li><li>把所制备的膜一起用Pt对电极和在所制备的溶液中的Ag / AgCl（3M KCl）中的参比电极。 </li><li>适用的0.10伏的电位与1.5分钟对于Ag / AgCl参比电极（ 图2d和2e）。注意：虽然每个恒电位仪软件会有所不同，所有的程序应该有输入线喜欢“集势“和”持续时间“，而这些数值可以填写请参考电位手动和附带的软件的更多细节。 </li><li>就拿电极从溶液中，并用Milli-Q水冲洗。 </li></ol></li><li>重复此过程，以获得至少10膜填充纳米线/纳米管，以获得足够的材料显著信号从H 2传感器。 </li></ol>纳米管和纳米线的6。提取<ol><li>切包含从载玻片上的纳米管或纳米线膜。 </li><li>传输这部分的膜的成聚丙烯离心管中。 </li><li>添加约2ml含1.0 M氢氧化钠来溶解氧化铝膜并释放纳米管或纳米线的成溶液的水溶液。后〜2小时，将膜应完全溶解（ 图2F和2G）。 </li><li>离心得到的〜19,000×g离心溶液中5英里N，除去过量的NaOH溶液，并加入新鲜的milli-Q水中。重复上述过程，至少3倍，以确保所有的NaOH已被删除。 </li><li>毕竟氢氧化钠已被移除，该水性悬浮液可以用于H 2的形成实验。 </li><li>或者，除去过量的水用于制备纳米管或纳米线的SEM的可视化后添加CH 2 Cl 2中或另一挥发性溶剂的纳米管和纳米线。重复离心至少3倍由挥发性溶剂完全取代所有的水。存入一小滴含有纳米管或纳米线的溶液，在小硅片。 </li></ol> H 2组实验氢传感器7，制备<ol><li>采取Pd基氢传感器。 </li><li>将传感器放在一个NS插头适合于石英管的顶部内侧。 </li><li>将传感器连接到一个标准的惠斯登电桥如图所示在图3中。 </li></ol> 8。光催化制氢的形成<ol><li>把水性纳米线的溶液在72毫升石英管。添加更多的水，直到总体积为10ml的水是在石英管内。再加入40ml甲醇。 </li><li>开始记录从钯基于H 2传感器的信号将其放置于石英管的顶部之前和监控信号的变化。 </li><li> 〜200秒稳定的信号后，把H 2传感器在石英管的顶部，同时打开UV光源开始实际测量。注意：在这些实验中，UV光源放置约10-15厘米的距离样品。 </li></ol>

The authors declare that they have no competing financial interests.
The author, Eddy J.B. Rodijk is currently an employee of Twente Solid State Technology B.V., The Netherlands.
The author, Michiel G. Maas is currently an employee of Henkel AG &amp; Co. KGaA, Germany.

在纳米线的模板电沉积非常重要的是，溅射的膜的顶部的金电极的背面侧的隔离。不经分离，该材料会优先沉积在金表面在膜的背面侧，而不是在孔隙内。这是因为离子到平面电极的扩散比扩散到膜孔快得多。沉积在金电极两侧另一个缺点是，所获得的曲线它不能与沉积的纳米线的数量和长度。在图4中 ，分几个阶段可以被识别为Ag的链段（a）或Ag核（B）的沉积。每一电沉积实验的第一阶段充电的双电层，这是伴随着突然增加电流慢慢减小，双电层达到其平衡。由于PCTE膜宝自Whatman水库有一个雪茄形，电流增大，在第二阶段，作为沉积的表面积增大，从而导致更多的材料沉积在同一时间，并且由于纳米线的表面速度供给反应物变得更接近入口的膜孔。在第三阶段中，在表面区域中的变化是最小的，从而导致增加的电流的较小的斜率，因为更快的反应物供应只的效果是明显的在此阶段。 请注意，在沉积同时含有金属和氧化物段分段的纳米线的情况下，电沉积在孔隙内的顺序应该采取的沉积相的溶解度在彼此的溶液明确地考虑确定。在这种情况下，Ag的段中的氧化锌段之前被沉积的ZnO作为将溶解在酸性的AgNO 3溶液。在形成含有贵金属的分段奈米线的情况下和一个更低的Noble 1， 例如 Pt和Ni，镍由铂电偶置换反应应考虑在内。此原电池置换反应可通过使用较大的超电势为在先前的出版物54中讨论被抑制。 使用任一PCTE或纳米线或纳米管的合成阳极氧化铝膜的选择通常是基于热退火步是否是理想的首选材料。未经退火步骤的必要性，PCTE膜更容易处理和相对良好的膜可以从市场上获得的。对于高温退火，采用阳极氧化铝膜是必需的。这些膜是不够灵活的聚碳酸酯膜，并且非常脆。有些商业阳极氧化铝膜是可用的，但使用的是2步自制的阳极氧化阳极氧化铝膜的质量要好得多。对于这一点，几个食谱可供55,56。 在Pd基H 2 </sub&gt;在本研究中使用的传感器是一种简单和相对低廉的方法，用于确定H 2是否已形成与否。不幸的是，它不适合于由于其交叉敏感性，易挥发的溶剂如甲醇，特性无法检测溶解的H 2在甲醇/水的溶液，并且它的非线性响应，在该曲线的形状看出定量测量在图8中 。定量测量可以在一个设置来执行与连接于甲醇/水混合物，它是专用设备，是不是在每个实验室可用上面的顶部空间气相色谱进样口。 H 2形成用银|氧化锌纳米线通常停止后〜48小时紫外线照射可见一斑终止气体形成气泡。这样做的原因的活性损失为ZnO的根据下面的反应57-60光腐蚀： 的ZnO +2 H +→Zn 2 +的+1/2 O 2（8） photocorroded的Ag的SEM图像|。氧化锌纳米线示于图9如从该图中可以看出，在ZnO段的表面变得更粗糙时紫外线照射相比， 图5的合成后原样的电线当悬浮另一个。批次的Ag |中在黑暗中48小时的相同溶液的ZnO纳米线，腐蚀的迹象被发现。这证实了所观察到的腐蚀确实起因于光腐蚀，而不是从电解腐蚀。在文献中，一些方法已被报道用于抑制氧化锌光腐蚀的，包括氧化锌的纳米颗粒与聚苯胺的单层上的TiO 2纳米管59,61,62杂交或C 60和ZnO纳米棒的嫁接。 轴向或径向分段纳米线模板电沉积是多段n的沉积一个完美的平台anowires，能够进行多个功能的一次，其中的Ag |氧化锌段可作为光催化元素的应用。在以前的出版物，包含六个部分的单个纳米线的SEM图像介绍：铂|金|铂|镍|银|氧化锌。这样的纳米线可用于自主运动（铂|金|铂），磁转向（Ni）和光催化的H 2的形成（银|氧化锌）53。 总之，一个简单的协议分割Ag的合成|氧化锌纳米线和同轴的TiO 2纳米线银通过模板化的电提供。利用光催化甲醇和水转化成H 2和CO 2在紫外光照射下的半定量的方法，以确定这些纳米线的光催化活性被证明。可以设想，这些金属氧化物的金属纳米线可以在多功能纳米线和纳米线的其他设备来使用。

由于它们的小尺寸和大的表面-体积比，纳米线是非常有前途的，可以在广泛的生物医学和纳米技术应用1使用一维物体。在文献中，包含具有功能性的单个组件的许多纳米线已经报道2-7。但是，当多个材料（金属，聚合物和金属氧化物）按顺序在单个纳米线结合，多功能的纳米线可以由8,9。当几个分部的单一纳米线内的连接，功能特性可能会出现的时候只使用了单个段中不存在。例如，据报道包含在一个单一的纳米线Au和Pt段纳米马达的自主移动时，放置在过氧化氢​​4。对于多段纳米线的形成合适的技术是渗透和模板电&lt;SUP&gt; 8,9。 1987年，彭纳和马丁是第一个发布使用模板电沉积的金纳米线的聚碳酸酯膜10的形成。从那时起，许多其他研究人员已经开始使用模板电沉积纳米线具有不同尺寸的合成，无论是使用聚碳酸酯轨道蚀刻膜（PCTE）或阳极氧化铝（AAO）膜和模板11。使用模板电沉积于纳米线合成的优点是它的高性价比的性质通常是温和的条件下进行电沉积，无论从金属，金属氧化物和/或聚合物，其创造的精确复制阴模能力形成的纳米线的可能性在模板中使用11。此外，分段的纳米线可以由两个或多个不同相位的连续沉积来形成，并且当两相之一的碳纳米管可以由模板电沉积制成，可制成含两个不同的阶段同轴纳米线。 金属氧化物可电沉积时的各金属离子是不溶于水溶液中的高pH值。供必要的氧，三种不同的前体都可以使用， 例如硝酸根离子12-15，过氧化氢​​13，16，17，和分子氧18。与使用硝酸根离子，如在该协议中，应用的电位高于-0.9V，相对于Ag / AgCl电极更负的导致了由硝酸盐还原在阴极19和20局部增加的pH值： NO 3 - + H 2 O + 2e的- →NO 2 - +2 OH - 。 （1） 当电解质溶液被加热到60-90℃，氧化锌纳米线将形成从沉淀的寻Ç氢氧化： ZN 2 + +2 OH - →氧化锌+ H 2 O。 （2） 在施加电势，以使工作电极，其被定位在模板电沉积孔隙底部，细孔内的pH值局部增加导致局部纳米线的形成。因为ZnO是n型半导体，反应（1）和（2）可以继续在氧化锌/电解质界面，造成结晶和致密氧化锌纳米线21，22的形成。 对于TiO 2的纳米管合成的方法有几种，但对于一个同轴结构的使用顺序电沉积过程中形成的，该电化学诱导溶胶-凝胶法是最合适的。首先由纳塔拉詹等人介绍了该方法的TiO 2薄膜的阴极电泳，于1996年23。并furtheŘ改善由Karuppuchamy 等人于2001年19，24。使用该方法，含氧硫酸钛（TiOSO 4）粉末溶解在过氧化氢 ​​后的peroxotitanate复合物的形成的水溶液（H 2 O 2）（钛（O 2）SO 4）： TiOSO 4 + H 2 O 2→的Ti（O 2）SO 4 + H 2 O。 （3） 在电势大于-0.9V，相对于Ag / AgCl电极更负时，pH在电极表面增加了硝酸盐还原（反应（1）），形成氢氧化钛凝胶19，20： 的Ti（O 2）SO 4 +2 OH - +（X +1）H 2 O→二氧化钛（OH）2 x高2 O + H 2 O 2 + SO 4 2 - 。 （4） Natar·阿贾恩等人使用差示热分析，发现水从周围283℃下的凝胶的热退火，这导致无定形的TiO 2相23的形成过程中除去。为一平面薄膜，当温度高于365℃，23，25增加，而结晶发生在525和550℃时的AAO模板用于25之间的温度下，结晶转变成锐钛矿相发生。 二氧化钛（OH）2·x高2 O→的TiO 2 +（X +1）H 2 O （5） 用AAO模板的孔径决定了固体纳米线或纳米管的开放是否将形成。沉积在具有小孔径（〜50 nm）的结果在纳米线形成20，26，同时施加一个孔里面相同的方法用直径较大（〜200 nm）的结果在一个模板纳米管的形成25。这是因为凝胶崩溃可以采取后去除多余水分的地方。 在70年代初期，藤岛和本田是第一个在紫外光下，这是实现由耦合到铂电极27，28金红石电极发布直接分解水的系统。从那时起，超过130的半导体材料被确定为光催化剂29-31。这些中，二氧化钛32-36，氧化锌37-40和氧化铁41,42是最广泛研究的材料中。这些材料的表面与体积之比可以显着增加时，纳米颗粒或纳米线的使用，从而提高催化效率29，30，43-49。 用于光催化Ag的建设|氧化锌纳米线，氧化锌，这是一种光敏正典型Ë半导体，是与银通过同一模板50内连续电连接。在这样的单个纳米线，ZnO的光电阳极和Ag阴极直接联接，而无需连接电极的外部电路，这是相对于在以往的光电化学电池的情况的需要。这简化了设备结构显着增加，并通过还原的系统中的欧姆损耗的效率。由于氧化锌（4.35 eV的对比真空）的电子亲和力的ZnO和Ag段被加上非常接近银（4.26 eV的对比真空）的功函数。这种诱导的两个阶段51，它允许在ZnO的导带激发的电子流向银，但反之之间的肖特基势垒的形成，从而禁止电子-空穴复合52的机会。可在60-90℃下，它提供了nanow的一种简单和成本有效的方式已经形成ZnO的活性纤锌矿相愤怒的形成。这是相对于那些需要在高温下的中间退火工序时，通过阴极电沉积制成大多数其它光活性氧化物。 甲醇和水转化为氢气和二氧化碳作为模型反应，以证明使用含有金属的分段的纳米线的和为UV光的影响下，自主的H 2形成的金属氧化物相。在该实验中，使用甲醇作为被氧化成CO 2的氧化锌段空穴清除剂，净反应如下 CH 3 OH + H 2 O + H +→CO 2 + H +，（6） 其中h +代表电子空穴。形成在所述的ZnO段中的质子减少到H 2在银表面上，对反应后 2H + + 2e中-594; H 2。 （7） 由于所需的反应（6）和（7）比ZnO的带隙（0.7和3.2电子伏特，分别）小得多的总能量，这一过程可以发生，而不需要外部电源。这个过程是在图1中示意性地示出。 在这个协议中，模板电沉积为同时含有金属和半导体相位分段和同轴纳米线形成的实验程序进行说明。一个程序分割的Ag形成|氧化锌纳米线的概述，以及形成的TiO 2纳米管及其随后的填充用的Ag，得到的同轴二氧化钛-银纳米线。此外，银的光催化活性|氧化锌纳米线被证明在辐照甲醇/水混合物转化成H 2和CO 2气体，紫外线灯采用Pd基传感器对H 2的检测。该协议的重点是两个不同的分段金属氧化物的制备及光催化特性|金属纳米线的模块，和一个更深入的治疗和多功能纳米线的一个例子可以在其他地方53被发现。这是使用同轴二氧化钛-银纳米线所使用的水分解反应也可以在其他地方25找到。

<table border="0" cellpadding="0" cellspacing="0" width="839">
	<tbody>
		<tr height="25">
			<td height="25" style="height:25px;width:279px;">Silver Nitrate (AgNO3)</td>
			<td style="width:195px;">Acros Organics</td>
			<td style="width:199px;">419351000</td>
			<td style="width:167px;">99+%</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:279px;">Boric Acid (H3BO3)</td>
			<td style="width:195px;">Sigma-Aldrich</td>
			<td style="width:199px;">202878-500G</td>
			<td style="width:167px;">99.99%</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:279px;">Nitric Acid (HNO3)</td>
			<td style="width:195px;">Acros Organics</td>
			<td style="width:199px;">124660010</td>
			<td style="width:167px;">65%</td>
		</tr>
		<tr height="46">
			<td height="46" style="height:46px;width:279px;">Zinc Nitrate Hexahydrate (Zn(NO3)2&#183;6H2O)</td>
			<td style="width:195px;">Sigma-Aldrich</td>
			<td style="width:199px;">228737-500G</td>
			<td style="width:167px;">98%</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:279px;">Dichloromethane (CH2Cl2)</td>
			<td style="width:195px;">Merck (Boom)</td>
			<td style="width:199px;">51006050100</td>
			<td style="width:167px;">99%</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:279px;">Titanium oxysulfate (TiOSO4)</td>
			<td style="width:195px;">Sigma-Aldrich</td>
			<td style="width:199px;">333980-500G</td>
			<td style="width:167px;">Synthesis grade</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:279px;">Hydrogen peroxide (H2O2)</td>
			<td style="width:195px;">Sigma-Aldrich</td>
			<td style="width:199px;">349887-500ML</td>
			<td style="width:167px;">35%</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:279px;">Nitric acid (HNO3)</td>
			<td style="width:195px;">Acros Organics</td>
			<td style="width:199px;">124660010</td>
			<td style="width:167px;">65%</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:279px;">Potassium nitrate (KNO3)</td>
			<td style="width:195px;">Acros Organics</td>
			<td style="width:199px;">P/6040/60</td>
			<td style="width:167px;">&#62;99%</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">Sodium hydroxide (NaOH)</td>
			<td style="width:195px;">Sigma-Aldrich</td>
			<td style="width:199px;">20606-0025</td>
			<td style="width:167px;">&#62;98%</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:279px;">Methanol (CH3OH)</td>
			<td style="width:195px;">Merck</td>
			<td style="width:199px;">1060121000</td>
			<td style="width:167px;">Dried &#8805;99.9%</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">Polycarbonate membranes 200 nm</td>
			<td style="width:195px;">Fisher Scientific</td>
			<td style="width:199px;">09-300-61</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">Anopore AAO membranes 200 nm</td>
			<td style="width:195px;">VWR</td>
			<td style="width:199px;">514-0523</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">Sputtering system</td>
			<td style="width:195px;">Perkin-Elmer</td>
			<td style="width:199px;">Model 2400</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">Microscope glass slides (Menzel)</td>
			<td style="width:195px;">VWR</td>
			<td style="width:199px;">631-0704</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">Autolab potentiostat with</td>
			<td rowspan="3" style="width:195px;">Metrohm-Autolab</td>
			<td style="width:199px;">PGSTAT 128N</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">- Pt sheet counter electrode</td>
			<td style="width:199px;">PT.SHEET</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">- Ag/AgCl in 3 M KCl reference electrode</td>
			<td style="width:199px;">60,733,100</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">Polypropylene Nunc centrifuge tubes</td>
			<td style="width:195px;">Fisher Scientific</td>
			<td style="width:199px;">12-565-286C</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">Centrifuge</td>
			<td style="width:195px;">Hermle</td>
			<td style="width:199px;">Z36HK</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">Pd-based hydrogen sensor</td>
			<td style="width:195px;">Kebaili</td>
			<td style="width:199px;">KHS-100</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:279px;">4x 15W Hg lamp UV source</td>
			<td style="width:195px;">Philips</td>
			<td style="width:199px;">Philips original home solaria</td>
			<td></td>
		</tr>
	</tbody>
</table>

preparation and use of photocatalytically active segmented ag|zno and coaxial tio2-ag nanowires made by templated electrodeposition

光催化活性纳米结构需要一个大的比表面积与许多催化活性位点的氧化还原半反应的存在，并快速电子（空穴）的扩散和电荷分离。纳米线呈现合适的架构来满足这些要求。沿轴向分割的Ag | ZnO和径向分段（同轴）的TiO 2 -银纳米线的直径为200纳米和6-20微米的长度是由模板电沉积的聚碳酸酯履带式蚀刻（PCTE）或阳极化的铝氧化物的细孔内进行（AAO）膜，分别。在光催化实验中，氧化锌和二氧化钛阶段担任光阳极和Ag作为阴极。没有外部电路需要连接两个电极，这是与传统的光电化学电池的一个关键优势。用于制造分段的Ag |氧化锌纳米线，所述Ag盐电解质代替形成的Ag段后，形成的ZnO段一ttached于Ag段。用于制造同轴电缆的TiO 2 -银纳米线，一TiO 2的凝胶首先由电化学诱导溶胶-凝胶法形成的。干燥和作为形成TiO 2的凝胶的热退火造成的结晶的TiO 2纳米管的形成。在TiO 2纳米管内随后的银电沉积工序导致形成的同轴二氧化钛-银纳米线。由于n型半导体（氧化锌或二氧化钛）和相同的纳米线中的金属（Ag）的组合，肖特基势垒是在两相之间的界面创建。为了证明这些纳米线的光催化活性，银|氧化锌纳米线的其中H 2气体后，分散在甲醇/水混合物的纳米线的紫外光照射检测光催化实验中使用。后照射17分钟，约0.2体积％的H 2气体被从悬浮液中〜0.1克的Ag检测|氧化锌纳米线在50毫升80％（体积）的甲醇水溶液。

电沉积过程中，也就是在工作电极和对电极之间测量的电流可以被可视化在它的曲线。由于电流是直接关系到沉积材料通过法拉第定律的量，观察到的电流是如何沉积所得的重要标志。典型的是曲线为Ag的沉积|氧化锌和二氧化钛-银纳米线示于图4中的Ag的典型SEM图像|氧化锌纳米线的TiO 2纳米管，同轴二氧化钛-银纳米线和TiO 2 /银纳米管可以是在图5和图6中发现，分别为。 使用电化学诱导溶胶 - 凝胶法对模板和Ag的顺序电镀内二氧化钛凝胶的沉积可导致取决于用于干燥凝胶的温度两种不同的结构。凝胶过夜，在100℃的结果孔德干燥nsation的凝胶，防止它在水中重新溶解。因为没有致密管状尚未形成在该温度下，银核被沉积在二氧化钛凝胶的内部。随后的退火在650℃下的结果在TiO 2的纳米管（ 图6c）掺入银纳米颗粒的形成中，由于二氧化钛凝胶的瓦解导致的Ag纳米粒子被运送到孔壁上。与此相反，前向银电沉积的二氧化钛凝胶的高温退火导致了固体的TiO 2纳米管的形成。在这种情况下，银纳米线可能这些管道内的沉积，导致形成的TiO 2的银纳米线具有同轴结构（ 图6b）。 分段的Ag的活动|在光催化分解水的ZnO纳米线可以使用在紫外光照射下，用甲醇/水的溶液进行调查，其中甲醇作为空穴清除剂。技术上SIMP是通过将一个H 2传感器的溶液的正上方（ 图7）中得到乐的方法来检测气态氢从溶液中不断变化的。该实验只检测H 2到达传感器的数量，从而形成H 2的实际量可能会更高一些的 H 2将保持溶解在甲醇/水相。由传感器检测出的信号是如图8a所示 。 图8b显示了变换到的实际的H 2形成的时限后的信号相同。当UV光源被接通（在图8a吨= 17.5分钟），所述信号大幅度下降，由于传感器的光灵敏度。这个下降信号后右，反应开始，因此此刻被定义为t = 0分钟在图8b中，对应的信号被定义为0 V.在试管的紫外线照射，这是可见的还小的气体bubblES形成的。由于所使用的传感器是轻度交敏感甲醇中，也包括没有纳米线的参比样品的测量。在紫外光照射下， 图8示出了从与纳米线的样品的信号比来自参考样品的信号更高。 在电势的增加为气态的H 2的形成，并从溶液中进化的量的相对度量。为了给定量估计为进化的 H 2的量，该传感器从光催化实验的潜在响应，用其在4％（体积） 的 H 2的N 2气流中的反应相比较。从比较中，据估计，所述Ag的紫外线照射17分钟|氧化锌纳米线导致约0.2体积％ 的 H 2中的气体体积在溶液上方的形成。由于〜是用来0.1克纳米线，这等于6.92×10 H 2释放速率<html> -6摩尔/小时·克作为参考，也进行单相或氧化锌纳米线的Ag实验。这些实验，这里没有显示，没有给出任何指示H 2的形成;既不是从气体形成气泡，也不从传感器信号。 <img alt="图1" fo:content-width="5in" src="/files/ftp_upload/51547/51547fig1highres.jpg" width="500" /> 图1分段银的工作原理|氧化锌纳米线的光催化分解水：（一 ）示意图，及（b）能量图。当紫外光被氧化锌吸收段，一个电子 - 空穴对被形成。在这样形成的电子流向的Ag相在那里它们被消耗的电化学还原半反应。空穴滞留在那里它被消耗在氧化半反应的氧化锌段。获得=“_blank”&gt;点击这里查看大图。 <img alt="图2" fo:content-width="5in" src="/files/ftp_upload/51547/51547fig2highres.jpg" width="500" /> 图2。采取的纳米线合成的连续步骤的示意图。 <img alt="图3" fo:content-width="5in" src="/files/ftp_upload/51547/51547fig3highres.jpg" width="500" /> 图3中的H 2传感器与惠斯登电桥的典型的工作电路。在这个方案中，针1至4指传感器的布线（引脚1为黑色，引脚2为蓝色，针3是白色的，引脚4为褐色）中，R h是加热器（150±50Ω）的电阻，R r是参考（1500±500Ω）的电阻，R s是所述传感器的电阻值（1，000±250Ω）。该传感器被连接到12伏电源，使0.5〜1.0 V施加到加热器和2.7 V施加到惠斯登电桥。V 出被连接到万用表/恒电位仪。旁边销2的电阻是可变的，并且可以以得到一个适当的基准进行调整。 <img alt="图4" fo:content-width="5in" src="/files/ftp_upload/51547/51547fig4highres.jpg" width="500" /> 图4的（A）的Ag典型它曲线|。氧化锌纳米线沉积，以及（b）TiO 2的银纳米线沉积的插图显示了银段（a）或Ag核的沉积的放大的曲线（b）。 <a href="https://www.jove.com/files/ftp_upload/51547/51547fig4highres.jpg" target="_blank">点击此处查看大图。</a> 。轴向分段的ZnO图5扫描电子显微镜（SEM）图片|银纳米线。 <img alt="图6" fo:content-width="5in" src="/files/ftp_upload/51547/51547fig6highres.jpg" width="500" /> 图6。SEM照片（一）TiO 2纳米管，（B）同轴的TiO 2银纳米线及（c）的TiO 2 /银纳米管。 <a href="https://www.jove.com/files/ftp_upload/51547/51547fig6highres.jpg" target="_blank">点击这里查看大图。</a> <img alt="图7" fo:content-width="5in" src="/files/ftp_upload/51547/51547fig7highres.jpg" width="500" /> 图7。典型设置的检测的H 2气体从光催化纳米线演变的基于钯的H 2传感器被放置在石英比色皿中的NS插头，并连接到放大器（参见图3）。该放大器是由一个12伏电源和信号从传感器被连接到一台电脑所获得的信号的图形表示万用表（或电位）读操作。 <a href="https://www.jove.com/files/ftp_upload/51547/51547fig7highres.jpg" target="_blank">点击这里查看大图。</a> <img alt="图8" fo:content-width="5in" src="/files/ftp_upload/51547/51547fig8highres.jpg" width="500" /> 图8选自Ag的紫外线照射在H 2传感器响应|。氧化锌纳米线在甲醇/水的溶液（红色线）和参照实验没有纳米线（蓝线）（a）信号作为由所测量的传感器; （二 ）信号在H 2的形成，其中在t的数据点=（ 一 ）17.5分钟被定义为（b）中的反应开始。 <a href="https://www.jove.com/files/ftp_upload/51547/51547fig8highres.jpg" target="_blank">点击这里查看大图。</a> <img alt="图9" fo:content-width="5in" src="/files/ftp_upload/51547/51547fig9highres.jpg" width="500" /> 图9 photocorroded银的SEM图像|后氧化锌纳米线48小时紫外线照射。

Watch this Scientific Journal Video about Preparation and Use of Photocatalytically Active Segmented Ag|ZnO and Coaxial TiO2-Ag Nanowires Made by Templated Electrodeposition at JoVE.com

Preparation and Use of Photocatalytically Active Segmented Ag|ZnO and Coaxial TiO2-Ag Nanowires Made by Templated Electrodeposition

Procedures are outlined to prepare segmented and coaxial nanowires via templated electrodeposition in nanopores. As examples, segmented nanowires consisting of Ag and ZnO segments, and coaxial nanowires consisting of a TiO2 shell and a Ag core were made. The nanowires were used in photocatalytic hydrogen formation experiments.

制备和使用光催化活性分段银|氧化锌和二氧化钛同轴<sub&gt; 2</sub&gt;银纳米线制成由模板电

Photocatalytically active nanostructures require a large specific surface area with the presence of many catalytically active sites for the oxidation and ...

preparation-use-photocatalytically-active-segmented-agzno-coaxial

Research

JoVE Journal

Engineering

Preparation and Use of Photocatalytically Active Segmented Ag|ZnO and Coaxial TiO2-Ag Nanowires Made by Templated Electrodeposition

21.6K 次观看.  University of Twente. Procedures are outlined to prepare segmented and coaxial nanowires via templated electrodeposition in nanopores. As examples, segmented nanowires consisting of Ag and ZnO segments, and coaxial nanowires consisting of a TiO2 shell and a Ag core were made. The nanowires were used in photocatalytic hydrogen formation experiments.

视频: Preparation and Use of Photocatalytically Active Segmented Ag|ZnO and Coaxial TiO2-Ag Nanowires Made by Templated Electrodeposition

Ultrahigh Density Array of Vertically Aligned Small-molecular Organic Nanowires on Arbitrary Substrates

In recent years &pi;-conjugated organic semiconductors have emerged as the active material in a number of diverse applications including large-area, low-cost displays, photovoltaics, printable and flexible electronics and organic spin valves. Organics allow (a) low-cost, low-temperature processing and (b) molecular-level design of electronic, optical and spin transport characteristics. Such features are not readily available for mainstream inorganic semiconductors, which have enabled organics to carve a niche in the silicon-dominated electronics market. The first generation of organic-based devices has focused on thin film geometries, grown by physical vapor deposition or solution processing. However, it has been realized that organic nanostructures can be used to enhance performance of above-mentioned applications and significant effort has been invested in exploring methods for organic nanostructure fabrication.	
A particularly interesting class of organic nanostructures is the one in which vertically oriented organic nanowires, nanorods or nanotubes are organized in a well-regimented, high-density array. Such structures are highly versatile and are ideal morphological architectures for various applications such as chemical sensors, split-dipole nanoantennas, photovoltaic devices with radially heterostructured "core-shell" nanowires, and memory devices with a cross-point geometry. Such architecture is generally realized by a template-directed approach. In the past this method has been used to grow metal and inorganic semiconductor nanowire arrays. More recently &pi;-conjugated polymer nanowires have been grown within nanoporous templates. However, these approaches have had limited success in growing nanowires of technologically important &pi;-conjugated small molecular weight organics, such as tris-8-hydroxyquinoline aluminum (Alq3), rubrene and methanofullerenes, which are commonly used in diverse areas including organic displays, photovoltaics, thin film transistors and spintronics.	
Recently we have been able to address the above-mentioned issue by employing a novel "centrifugation-assisted" approach. This method therefore broadens the spectrum of organic materials that can be patterned in a vertically ordered nanowire array. Due to the technological importance of Alq3, rubrene and methanofullerenes, our method can be used to explore how the nanostructuring of these materials affects the performance of aforementioned organic devices. The purpose of this article is to describe the technical details of the above-mentioned protocol, demonstrate how this process can be extended to grow small-molecular organic nanowires on arbitrary substrates and finally, to discuss the critical steps, limitations, possible modifications, trouble-shooting and future applications.

We report a simple method for fabricating an ultrahigh density array of vertically ordered small-molecular organic nanowires. This method allows for synthesis of complex heterostructured hybrid nanowire geometries, which can be inexpensively grown on arbitrary substrates. These structures have potential applications in organic electronics, optoelectronics, chemical sensing, photovoltaics and spintronics.

超高密度垂直对齐的任意基质的小分子有机纳米线阵列

In  recent years &pi;-conjugated  organic semiconductors have emerged as the active material in a number of  diverse applications including large-area, ...

科研

工程学

Monolayer Contact Doping of Silicon Surfaces and Nanowires Using Organophosphorus Compounds

Monolayer Contact Doping (MLCD) is a simple method for doping of surfaces and nanostructures1. MLCD results in the formation of highly controlled, ultra shallow and sharp doping profiles at the nanometer scale. In MLCD process the dopant source is a monolayer containing dopant atoms.
In this article a detailed procedure for surface doping of silicon substrate as well as silicon nanowires is demonstrated. Phosphorus dopant source was formed using tetraethyl methylenediphosphonate monolayer on a silicon substrate. This monolayer containing substrate was brought to contact with a pristine intrinsic silicon target substrate and annealed while in contact. Sheet resistance of the target substrate was measured using 4 point probe. Intrinsic silicon nanowires were synthesized by chemical vapor deposition (CVD) process using a vapor-liquid-solid (VLS) mechanism; gold nanoparticles were used as catalyst for nanowire growth. The nanowires were suspended in ethanol by mild sonication. This suspension was used to dropcast the nanowires on silicon substrate with a silicon nitride dielectric top layer. These nanowires were doped with phosphorus in similar manner as used for the intrinsic silicon wafer. Standard photolithography process was used to fabricate metal electrodes for the formation of nanowire based field effect transistor (NW-FET). The electrical properties of a representative nanowire device were measured by a semiconductor device analyzer and a probe station.

A detailed procedure for surface doping of Silicon interfaces is provided. The ultra-shallow surface doping is demonstrated by using phosphorus containing monolayers and rapid annealing process. The method can be used for doping of macroscopic area surfaces as well as nanostructures.

Monolayer Contact Doping (MLCD) is a simple method for doping of surfaces and nanostructures1. MLCD results in the formation of highly controlled, ultra ...

Evaluating Plasmonic Transport in Current-carrying Silver Nanowires

Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information support1,2,3. In this context, metal nanowires are especially desirable for realizing dense routing networks4. A prerequisite to operate such shared nanowire-based platform relies on our ability to electrically contact individual metal nanowires and efficiently excite surface plasmon polaritons5 in this information support. In this article, we describe a protocol to bring electrical terminals to chemically-synthesized silver nanowires6 randomly distributed on a glass substrate7. The positions of the nanowire ends with respect to predefined landmarks are precisely located using standard optical transmission microscopy before encapsulation in an electron-sensitive resist. Trenches representing the electrode layout are subsequently designed by electron-beam lithography. Metal electrodes are then fabricated by thermally evaporating a Cr/Au layer followed by a chemical lift-off. The contacted silver nanowires are finally transferred to a leakage radiation microscope for surface plasmon excitation and characterization8,9. Surface plasmons are launched in the nanowires by focusing a near infrared laser beam on a diffraction-limited spot overlapping one nanowire extremity5,9. For sufficiently large nanowires, the surface plasmon mode leaks into the glass substrate9,10. This leakage radiation is readily detected, imaged, and analyzed in the different conjugate planes in leakage radiation microscopy9,11. The electrical terminals do not affect the plasmon propagation. However, a current-induced morphological deterioration of the nanowire drastically degrades the flow of surface plasmons. The combination of surface plasmon leakage radiation microscopy with a simultaneous analysis of the nanowire electrical transport characteristics reveals the intrinsic limitations of such plasmonic circuitry.

Silver nanowires can simultaneously transport electrons and optical information in the form of surface plasmons. A procedure is described here to realize such a shared circuitry and the limitations at propagating both information carriers are evaluated.

Plasmonics is an emerging technology capable of simultaneously transporting a plasmonic signal and an electronic signal on the same information ...

In Situ Neutron Powder Diffraction Using Custom-made Lithium-ion Batteries

Li-ion batteries are widely used in portable electronic devices and are considered as promising candidates for higher-energy applications such as electric vehicles.1,2 However, many challenges, such as energy density and battery lifetimes, need to be overcome before this particular battery technology can be widely implemented in such applications.3 This research is challenging, and we outline a method to address these challenges using in situ NPD to probe the crystal structure of electrodes undergoing electrochemical cycling (charge/discharge) in a battery. NPD data help determine the underlying structural mechanism responsible for a range of electrode properties, and this information can direct the development of better electrodes and batteries.
We briefly review six types of battery designs custom-made for NPD experiments and detail the method to construct the &#8216;roll-over&#8217; cell that we have successfully used on the high-intensity NPD instrument, WOMBAT, at the Australian Nuclear Science and Technology Organisation (ANSTO). The design considerations and materials used for cell construction are discussed in conjunction with aspects of the actual in situ NPD experiment and initial directions are presented on how to analyze such complex in situ data.

In Situ Neutron Powder Diffraction Using Custom-made Lithium-ion Batteries

We describe the design and construction of an electrochemical cell for the examination of electrode materials using in situ neutron powder diffraction (NPD). We briefly comment on alternate in situ NPD cell designs and discuss methods for the analysis of the corresponding in situ NPD data produced using this cell.

原位中子衍射用特制的锂离子电池

Li-ion batteries are widely used in portable electronic devices and are considered as promising candidates for higher-energy applications such as electric ...

A Cost-effective and Reliable Method to Predict Mechanical Stress in Single-use and Standard Pumps

Pumps are mainly used when transferring sterile culture broths in biopharmaceutical and biotechnological production processes. However, during the pumping process shear forces occur which can lead to qualitative and/or quantitative product loss. To calculate the mechanical stress with limited experimental expense, an oil-water emulsion system was used, whose suitability was demonstrated for drop size detections in bioreactors1. As drop breakup of the oil-water emulsion system is a function of mechanical stress, drop sizes need to be counted over the experimental time of shear stress investigations. In previous studies, the inline endoscopy has been shown to be an accurate and reliable measurement technique for drop size detections in liquid/liquid dispersions. The aim of this protocol is to show the suitability of the inline endoscopy technique for drop size measurements in pumping processes. In order to express the drop size, the Sauter mean diameter d32 was used as the representative diameter of drops in the oil-water emulsion. The results showed low variation in the Sauter mean diameters, which were quantified by standard deviations of below 15%, indicating the reliability of the measurement technique.

Shear stress investigations on an oil-water emulsion system result in drop breakup over the experimental time. To count drop sizes in pumping processes, the suitability of inline endoscopy was successfully demonstrated in this protocol.

高性价比和可靠的方法来预测机械应力一次性使用和标准泵

Pumps are mainly used when transferring sterile culture broths in biopharmaceutical and biotechnological production processes. However, during the pumping ...

Resonance Raman Spectroscopy of Extreme Nanowires and Other 1D Systems

This paper briefly describes how nanowires with diameters corresponding to 1 to 5 atoms can be produced by melting a range of inorganic solids in the presence of carbon nanotubes. These nanowires are extreme in the sense that they are the limit of miniaturization of nanowires and their behavior is not always a simple extrapolation of the behavior of larger nanowires as their diameter decreases. The paper then describes the methods required to obtain Raman spectra from extreme nanowires and the fact that due to the van Hove singularities that 1D systems exhibit in their optical density of states, that determining the correct choice of photon excitation energy is critical. It describes the techniques required to determine the photon energy dependence of the resonances observed in Raman spectroscopy of 1D systems and in particular how to obtain measurements of Raman cross-sections with better than 8% noise and measure the variation in the resonance as a function of sample temperature. The paper describes the importance of ensuring that the Raman scattering is linearly proportional to the intensity of the laser excitation intensity. It also describes how to use the polarization dependence of the Raman scattering to separate Raman scattering of the encapsulated 1D systems from those of other extraneous components in any sample.

The paper describes a method for producing extreme nanowires by melt infiltration into carbon nanotubes and how 1D systems may be characterized and investigated using Resonance Raman Spectroscopy to determine vibrational and optical excitation energies.

至尊纳米线和其他维系统的共振拉曼光谱

This paper briefly describes how nanowires with diameters corresponding to 1 to 5 atoms can be produced by melting a range of inorganic solids in the ...

A Fabrication Method for Highly Stretchable Conductors with Silver Nanowires

Stretchable electronics are identified as a key technology for electronic applications in the next generation. One of the challenges in fabrication of stretchable electronic devices is the preparation of stretchable conductors with great mechanical stability. In this study, we developed a simple fabrication method to chemically solder the contact points between silver nanowire (AgNW) networks. AgNW nanomesh was first deposited on a glass slide via spray coating method. A reactive ink composed of silver nanoparticle (AgNPs) precursors was applied over the spray coated AgNW thin films. After heating for 40 min, AgNPs were preferentially generated over the nanowire junctions to solder the AgNW nanomesh, and reinforced the conducting network. The chemically modified AgNW thin film was then transferred to polyurethane (PU) substrates by casting method. The soldered AgNW thin films on PU exhibited no obvious change in electrical conductivity under stretching or rolling process with elongation strains up to 120%.

A simple synthesis method is used to chemically solder silver nanowire thin film to fabricate highly stretchable and conductive metal conductors.

对于高伸缩的导线与银纳米线制作方法

Stretchable electronics are identified as a key technology for electronic applications in the next generation. One of the challenges in fabrication of ...

Preparation and 3D Tracking of Catalytic Swimming Devices

We report a method to prepare catalytically active Janus colloids that "swim" in fluids and describe how to determine their 3D motion using fluorescence microscopy. One commonly deployed method for catalytically active colloids to produce enhanced motion is via an asymmetrical distribution of catalyst. Here this is achieved by spin coating a dispersed layer of fluorescent polymeric colloids onto a flat planar substrate, and then using directional platinum vapor deposition to half coat the exposed colloid surface, making a two faced "Janus" structure. The Janus colloids are then re-suspended from the planar substrate into an aqueous solution containing hydrogen peroxide. Hydrogen peroxide serves as a fuel for the platinum catalyst, which is decomposed into water and oxygen, but only on one side of the colloid. The asymmetry results in gradients that produce enhanced motion, or "swimming". A fluorescence microscope, together with a video camera is used to record the motion of individual colloids. The center of the fluorescent emission is found using image analysis to provide an x and y coordinate for each frame of the video. While keeping the microscope focal position fixed, the fluorescence emission from the colloid produces a characteristic concentric ring pattern which is subject to image analysis to determine the particles relative z position. In this way 3D trajectories for the swimming colloid are obtained, allowing swimming velocity to be accurately measured, and physical phenomena such as gravitaxis, which may bias the colloids motion to be detected.

A method to prepare catalytically active Janus colloids that can "swim" in fluids and determine their 3D trajectories is presented.

催化游泳器件的制备及其三维跟踪

We report a method to prepare catalytically active Janus colloids that "swim" in fluids and describe how to determine their 3D motion using fluorescence ...

Use of Sacrificial Nanoparticles to Remove the Effects of Shot-noise in Contact Holes Fabricated by E-beam Lithography

Nano-patterns fabricated with extreme ultraviolet (EUV) or electron-beam (E-beam) lithography exhibit unexpected variations in size. This variation has been attributed to statistical fluctuations in the number of photons/electrons arriving at a given nano-region arising from shot-noise (SN). The SN varies inversely to the square root of a number of photons/electrons. For a fixed dosage, the SN is larger in EUV and E-beam lithographies than for traditional (193 nm) optical lithography. Bottom-up and top-down patterning approaches are combined to minimize the effects of shot noise in nano-hole patterning. Specifically, an amino-silane surfactant self-assembles on a silicon wafer that is subsequently spin-coated with a 100 nm film of a PMMA-based E-beam photoresist. Exposure to the E-beam and the subsequent development uncover the underlying surfactant film at the bottoms of the holes. Dipping the wafer in a suspension of negatively charged, citrate-capped, 20 nm gold nanoparticles (GNP) deposits one particle per hole. The exposed positively charged surfactant film in the hole electrostatically funnels the negatively charged nanoparticle to the center of an exposed hole, which permanently fixes the positional registry. Next, by heating near the glass transition temperature of the photoresist polymer, the photoresist film reflows and engulfs the nanoparticles. This process erases the holes affected by SN but leaves the deposited GNPs locked in place by strong electrostatic binding. Treatment with oxygen plasma exposes the GNPs by etching a thin layer of the photoresist. Wet-etching the exposed GNPs with a solution of I2/KI yields uniform holes located at the center of indentations patterned by E-beam lithography. The experiments presented show that the approach reduces the variation in the size of the holes caused by SN from 35% to below 10%. The method extends the patterning limits of transistor contact holes to below 20 nm.

Uniformly sized nanoparticles can remove fluctuations in contact hole dimensions patterned in poly(methyl methacrylate) (PMMA) photoresist films by electron beam (E-beam) lithography. The process involves electrostatic funneling to center and deposit nanoparticles in contact holes, followed by photoresist reflow and plasma- and wet-etching steps.

牺牲纳米颗粒使用删除散粒噪声的影响通过电子束光刻装配式接触孔

Nano-patterns fabricated with extreme ultraviolet (EUV) or electron-beam (E-beam) lithography exhibit unexpected variations in size. This variation has ...

Preparation of Liquid Crystal Networks for Macroscopic Oscillatory Motion Induced by Light

A strategy based on doped liquid crystalline networks is described to create mechanical self-sustained oscillations of plastic films under continuous light irradiation. The photo-excitation of dopants that can quickly dissipate light into heat, coupled with anisotropic thermal expansion and self-shadowing of the film, gives rise to the self-sustained deformation. The oscillations observed are influenced by the dimensions and the modulus of the film, and by the directionality and intensity of the light. The system developed offers applications in energy conversion and harvesting for soft-robotics and automated systems.
The general method described here consists of creating free-standing liquid crystalline films and characterizing the mechanical and thermal effects observed. The molecular alignment is achieved using alignment layers (rubbed polyimide), commonly used in the display manufacturing industry. To obtain actuators with large deformation, the mesogens are aligned and polymerized in a splay/bend configuration, i.e., with the director of the liquid crystals (LCs) going gradually from planar to homeotropic through the film thickness. Upon irradiation, the mechanical and thermal oscillations obtained are monitored with a high-speed camera. The results are further quantified by image analysis using an image processing program.

The goal of the protocol is to create liquid crystalline polymer films that can mechanically oscillate under continuous light irradiation. We describe in great detail the conception of free-standing films, from the liquid crystal alignment method to the photo-actuation. The experimental protocol applied to prepare this material is broadly applicable.

光诱导的宏观振荡运动液晶网络的制备

A strategy based on doped liquid crystalline networks is described to create mechanical self-sustained oscillations of plastic films under continuous ...