Name: dye-sensitized solar cells and light capture
Uploaded: 2023-04-30T06:54:00.000Z
Duration: 10 min 30 s
Channel: JoVE

K12 Standards

north-carolina-k-12-science-standard-course-of-study

NC K-12 Science Standard Course of Study

9-12

Earth and Environmental Science

Earth and Human Activity

ESS.EES.5.4

Dye-sensitized Solar Cells

1. 二氧化钛的制备2 粘贴
<ol>
	<li>称取6 g胶体TiO2粉末，置于研钵中。</li>
	<li>小心向TiO2中加入2–3 mL醋，用研杵开始研磨悬浮液，直至形成均匀的糊状物。研磨的目的是打散粉末中的团聚颗粒。</li>
	<li>在研磨过程中，以约1 mL为增量继续添加醋，总添加量至约9 mL。每次添加前，应确保糊状物质地均匀且无颗粒。最终的糊状物应较为浓稠，但不能过于黏稠而无法从滴瓶中挤出。</li>
	<li>将1滴洗洁精加入1 mL蒸馏水中，轻轻混合。</li>
	<li>将洗洁精溶液加入TiO2悬浮液中，轻轻搅拌，注意避免产生气泡。</li>
	<li>让悬浮液静置平衡15分钟。洗洁精作为表面活性剂，有助于使悬浮液更易在玻璃表面铺展成均匀的薄膜。</li>
</ol>
2. 在玻璃上沉积 TiO2
<ol>
	<li>清洁两片导电玻璃片。用乙醇浸湿一张无尘纸，擦拭两片导电玻璃片以清洁表面。将清洁后的玻璃片放置在一张新的无尘纸上。</li>
	<li>确定玻璃片的导电面。将万用表调至欧姆档，用两个探针同时接触玻璃片的一侧表面。若读数在 10 至 30 Ω 之间，则该侧为导电面；若读数为 0 Ω，则为非导电面。</li>
	<li>对玻璃片进行遮蔽。将一片玻璃的导电面朝上放置，另一片的导电面朝下放置。小心保持两片玻璃相互接触，并用胶带将其固定在实验台面上。在玻璃片四边中的三边贴上胶带，确保每边约有 5–8 mm 的区域被胶带覆盖（图 4）。用力按压胶带，确保无气泡产生。</li>
	<li>涂覆 TiO2 浆料。使用玻璃棒，在玻璃片被胶带遮蔽的上边缘处涂上一条薄薄的浆料线。用玻璃棒小心地将浆料沿玻璃片长度方向向下滚动，再向上滚回。重复此操作 2–3 次，过程中不抬起玻璃棒，直至形成均匀的薄膜。
	<ol>
		<li>若薄膜不均匀，只需用无尘纸将其擦除，用乙醇清洁玻璃片表面，待干燥后重新操作。</li>
	</ol>
	</li>
	<li>让薄膜稍作干燥，然后小心地从玻璃片上移除胶带。带有 TiO2 薄膜的一侧应位于导电面上。另一片玻璃片可清洁后留待后续使用。</li>
	<li>退火处理 TiO2 薄膜。小心地将玻璃片（TiO2 面朝上）放置于设定为 450 °C 的加热板上。观察 TiO2 薄膜颜色逐渐变深至紫褐色，随后恢复为白色。此时关闭加热板，让薄膜缓慢冷却。若冷却过快，玻璃片可能发生开裂或破碎。</li>
	<li>使用直尺测量薄膜覆盖的表面积，并记录该数值。</li>
</ol>
<img alt="静电平衡示意图；用于电学实验的导电表面方向及胶带排列。" src="/files/ftp_upload/10328/10328fig4.jpg" data-altupdatedat="1761830439000" data-alt="图 4"> 
图 4. 在玻璃上沉积 TiO2。
3. 用染料对TiO2薄膜进行染色
<ol>
	<li>取少量黑莓、树莓或樱桃放入研钵中，用研杵将其研碎。</li>
	<li>将溶液通过咖啡滤纸过滤至培养皿中。必要时可向果汁中加入几毫升水。</li>
	<li>将冷却后的TiO2薄膜正面朝下放入培养皿中。注意不要刮掉任何TiO2。让染料吸附在薄膜上，此过程可能需要数分钟。</li>
	<li>当薄膜完全被覆盖后（应呈深红色或紫色，无白色斑点），用镊子夹起载玻片（注意仅接触玻璃部分，避免触碰薄膜），先用水冲洗，再用乙醇冲洗。用无尘纸轻轻吸干薄膜表面，并立即使用。
	<ol>
		<li>若不立即使用，应将薄膜存放在含有pH为3-5的乙酸的培养皿中，盖上皿盖并用铝箔包裹。</li>
	</ol>
	</li>
</ol>
4. 制备对电极
<ol>
	<li>使用另一块导电玻璃片，重复步骤 2.1–2.2。</li>
	<li>将碳催化剂涂覆在导电面。用镊子夹住载玻片，使导电面朝下，置于本生灯火焰尖端上方。移动载玻片，使烟灰均匀沉积在整个表面，但时间不超过 30 秒。待载玻片冷却后，用棉签擦拭载玻片一侧边缘的烟灰。
	<ol>
		<li>或者，使用 HB 铅笔在整个导电表面均匀涂上石墨。这种方法可得到更坚固的电极，但性能较差。</li>
	</ol>
	</li>
</ol>
5. 组装太阳能电池
<ol>
	<li>将染色后的薄膜晾干。用乙醇冲洗，并将其放置在无尘纸上。用另一张无尘纸轻轻吸干薄膜表面。薄膜必须完全干燥，以免影响电解质溶液。</li>
	<li>将电极膜面朝上，轻轻将碳涂层电极置于其上（碳面朝下）。确保两片玻璃片错开一定距离，以便两个电极的暴露部分均可连接导线。在错开的玻璃片两侧各夹上一个文件夹夹子。</li>
	<li>沿玻璃片的一侧边缘滴加数滴电解质溶液，通过交替开合夹子，小心地打开/闭合电池的两侧。确保所有染色区域均与电解质溶液接触，如有必要，重复步骤5.2。</li>
	<li>用无尘纸和乙醇擦去暴露区域多余的电解质。</li>
	<li>将鳄鱼夹固定在太阳能电池的两个暴露电极端。</li>
</ol>
6. 测定细胞性能
注意：理想情况下，这些测量应在室外进行。但如果天气条件不允许，也可在室内使用卤素灯进行。所有测量过程中均不得移动细胞，以确保在完全相同的条件下完成测量。
<ol>
	<li>确保将电池的方向调整为二氧化钛（TiO2）薄膜朝上，面向太阳，并在电池上方放置聚碳酸酯盖板，以保护电池免受紫外线损伤。</li>
	<li>将负极（涂有TiO2的玻璃）连接到万用表的负极导线，将正极（C）连接到万用表的正极导线（图5）。</li>
	<li>将万用表调至电压档，测量电压。此值为开路电位（零电流时的最大电压）。用手指或不透明物体遮盖电池，以确认电压下降。</li>
	<li>将万用表调至毫安档（mA），测量最大电流。此值为短路电流（零电压时的最大电流）。用手指遮盖电池，以确认电流下降。</li>
	<li>使用500-Ω电位器作为可变负载，记录完整的电流-电压曲线。
	<ol>
		<li>确定电位器上的哪个引线是中心抽头。该引线可实现电阻的调节。为此，将万用表（调至欧姆档）连接到电位器的两个引线上，并调节电位器的电阻，观察电阻是否发生变化。对另外两组引线组合重复此操作。在三组组合中，应有两组显示出电阻变化。在两组产生变化的组合中均被使用的引线即为中心抽头，其余两个引线在功能上是相同的。</li>
		<li>按照 图5（右图）所示连接电路。</li>
		<li>将电位器调至最大（或最小）电阻，记录此时的电流和电压。</li>
		<li>以小幅度逐步改变电位器的电阻，记录对应的电流和电压，以获取覆盖电位器整个调节范围的多个数据点。测量过程中务必不要移动电池。当电流开始变化时，应采集较多的数据点；在电流保持稳定时，可采集较少的数据点。</li>
	</ol>
	</li>
</ol>
<img alt="测量电压-电流及可变负载配置的太阳能电池电路图。" src="/files/ftp_upload/10328/10328fig5.jpg" data-altupdatedat="1761830439000" data-alt="图 5"> 
图 5。 用于测量开路电位和短路电流（左，步骤 6.3 和 6.4）以及记录 I-V 曲线（右）的电路图。

本视频展示了简易染料敏化太阳能电池的制备与分析过程。
太阳能电池正变得越来越普遍，目前有许多研究致力于提升其性能。基于硅半导体的传统太阳能电池被用于制造在太空和地面使用的太阳能电池板。丹佛国际机场充分利用科罗拉多州阳光充足的气候条件，建有四组太阳能阵列，可满足机场6%的能源需求。
染料敏化太阳能电池（DSSCs）的效率可达15%7&#160;，相比之下，传统低成本商用硅基太阳能电池板的效率为14–17%。尽管DSSCs的工作效率具有竞争力，但其材料（如钌染料）成本较高，限制了其在大规模应用中的推广。DSSCs可能面临的最大缺点是使用了对温度变化敏感的液态电解质。在低温下，液态电解质可能冻结，从而停止发电并/或导致太阳能电池板结构损坏；在高温下，液态电解质会膨胀，使得电池板的密封变得困难。

染料敏化太阳能电池

来源：Tamara M. Powers，德克萨斯农工大学化学系&amp;#38;M 大学
当今现代社会需要消耗大量能源。尽管我们通过煤炭和石油等化石燃料获取能源，但这些资源不可再生，因此供应有限。为了维持全球的生活方式，我们必须从可再生能源中获取能源。就资源丰富程度而言，最具前景的可再生能源是太阳，它所提供的太阳能足以完全满足地球能源需求的数倍以上。
那么，我们如何从太阳中获取能量呢？自然界最先解决了这一问题：光合作用是植物将水和二氧化碳转化为碳水化合物和氧气的过程。该过程发生在植物的叶片中，依赖于使叶片呈现绿色的叶绿素色素。正是这些有色分子吸收了太阳光的能量，而被吸收的能量则驱动了化学反应的进行。
1839年，时年19岁的法国物理学家埃德蒙·贝克勒尔（Edmond Becquerel）在其父亲的实验室中进行实验，制造出了首个光伏电池。他将连接有铂电极的酸性氯化银溶液暴露于光照下，产生了电压和电流。1&#160;许多发现与进展是在19世纪后期取得的th 以及前半部分的20th 20世纪，直到1954年，贝尔实验室才研制出首个实用的太阳能电池。自1950年代起，太阳能电池被用于为空间卫星提供电力。2
太阳能电池是一种利用光产生电流的电子器件。本视频展示了其中一种电池——染料敏化太阳能电池（DSSC）的制备与测试过程。该技术最初由加州大学伯克利分校的Brian O'Regan和Michael Grätzel发明，随后Grätzel在瑞士洛桑联邦理工学院继续研究，最终于1991年研制出首个高效率的DSSC。3&#160;这类太阳能电池与植物相似，利用染料来帮助捕获太阳的能量。

针对步骤 6.5.3–6.5.4 中采集的每个数据点，计算电流密度（mA/cm2）和功率密度（mW/cm2）。计算电流密度时，将电流除以步骤 2.7 中确定的薄膜表面积。计算功率密度时，将电压乘以电流密度。绘制在步骤 6.3、6.4 以及 6.5.3–6.5.4 中采集的数据的电流（mA）与电压（mV）关系图。对所有数据绘制电流密度与电压的关系图。该曲线应接近其&#34;拐点&#34;。通过将最大功率（mW/cm2）除以入射太阳光功率（取为 800–1,000 W/m2），再乘以 100%，计算太阳光到电能的转换效率。
在太阳能电池文献中，数据分析和I-V曲线的绘制是用于比较电池性能的标准方法。测得的开路电压应在0.3至0.5 V之间，短路电流密度应达到1-2 mA/cm2。

来源：德克萨斯农工大学化学系，塔玛拉·M·鲍尔斯（Tamara M. Powers）  
当今现代社会需要消耗大量能源。虽然……

染料敏化太阳能电池是传统半导体光伏电池的一种有前景的替代方案，近年来已具备商业可行性。染料敏化电池虽然效率较低，但其独特优势在于即使在高温和高入射光角度条件下仍能持续稳定地产生电能，在弱光环境下产生的电能比硅基太阳能电池高出近50%。这类电池的制造工艺显著简便，并可使用天然丰富、基于植物的色素作为染料。本视频展示了染料敏化太阳能电池的工作原理，演示了在实验室中利用植物色素制备测试样品的基本操作步骤，并讨论了若干应用实例。所有太阳能电池都依赖于光将能量传递给电子以产生电流的能力。在单个原子中，电子被限制在离散的能级上。然而，当它们吸收光子后，电子会暂时跃迁到更高的能级，从而在较低的能级上留下一个空穴。当两个原子彼此靠近时，它们会扰动对方的电子，从而形成电子可以占据的新的能级。随着更多原子的加入，会形成更多的能级，最终合并成密集的能带。在半导体中，未占据的能级形成高能量的导带，而已占据的能级则形成低能量的价带。两者之间的能量差称为“带隙能量”。当一个具有带隙能量的光子撞击一个电子时，该电子将被激发，留下一个空穴。电子和空穴都可以在原子间传导，直到它们重新复合。现在我们已经了解了半导体如何吸收光能，接下来让我们看看如何在染料敏化太阳能电池中利用这一现象。与硅太阳能电池不同，染料敏化太阳能电池将光吸收过程与电流传输过程分离，从而降低复合速率。电池包含一种敏化染料、一层半导体、一种电解质以及两个电极。该半导体是一种稳定的介电材料，例如锐钛矿型 TiO₂。电解质通常为有机碘化物，而对电极则为耐腐蚀且耐高温的材料，通常为铂或碳。该半导体具有介孔结构，并含有单层吸附的染料。当染料中的电子被光子激发后，会立即注入半导体的导带中。半导体将电子传递至光电极，进而传递至电路。电子通过对电极返回，在对电极处，耗尽的电解质被还原，从而完成循环。有效的染料可响应整个可见光谱。早期的染料包括有机钌配合物，这些染料在红外区域具有较高的转化效率，但成本高昂且难以制备。基于植物的光敏色素（如类胡萝卜素和花青素）则更为丰富且实用，尽管效率较低。这些是基本原理。现在让我们来考察一下实验室中的一项基础操作流程。此处演示的实验步骤可利用常见的前体试剂和实验室材料，快速制备并测试染料敏化太阳能电池。首先，将6 g锐钛矿型TiO2粉末加入研钵中。加入2–3 mL醋，研磨悬浮液以打碎结块。以1 mL为增量，分次加入醋并持续研磨，直至总共加入9 mL。最终得到的糊状物应均匀一致。接下来，通过将一滴洗洁精与1 mL蒸馏水轻轻混合，制备表面活性剂溶液。将表面活性剂溶液轻轻混入糊状物中，注意避免产生气泡。让悬浮液静置平衡使用浸有乙醇的低绒布清洁两片涂有 SnO₂ 的导电玻璃片。使用万用表确定其导电面。导电面的电阻应为 10–30 ?。将载玻片用胶带固定在实验台上，一片导电面朝上，另一片导电面朝下，使5-8 mm区域被遮蔽且无气泡。使用玻璃棒在导电面的顶端边缘均匀涂上一层薄薄的浆料。让薄膜略微干燥，然后移除胶带。将载玻片导电面朝上放置于加热板上烘干。薄膜首先会变暗呈紫褐色，随后变白。当出现此现象时，关闭加热板，但仍保持载玻片置于其上。待其冷却至室温后，记录薄膜的表面积。为制备对电极，先清洁第二片导电玻璃片。将碳催化剂涂覆在导电面。用镊子夹住导电面，在打火机火焰上方灼烧。收集烟灰，时间不超过30秒。用镊子调整玻璃片方向，以同样方式将剩余的角落覆盖上烟灰，确保整片玻璃表面均被覆盖。电极制备完成后，让我们来构建染料敏化太阳能电池。使用刮刀在烧杯中压碎少量树莓、黑莓或樱桃。然后用咖啡滤纸将溶液过滤至培养皿中，必要时可加入几滴蒸馏水。使用镊子将光电极放置于培养皿中，导电面朝下，注意不要刮伤薄膜。染色完成后，小心取出载玻片，检查是否可见白色斑块。用乙醇冲洗载玻片并吸干。将对电极倒置在薄膜上，保持载玻片之间有一定的偏移。用长尾夹夹住载玻片的边缘。沿边缘滴加几滴电解质，轻轻打开长尾夹使电解质渗入薄膜。此时，电池已准备就绪，可进行操作。准备在卤素灯下测量电池性能。将电池放置成光电极面向卤素灯。使用万用表测量开路电位和短路电流。接下来，将电池连接至一个500 ??电位器，以构建文本方案中所示的电路。逐步增加电位器的电阻，并使用万用表测量电压和电流。收集的数据用于绘制电流-电压曲线，该曲线描述了太阳能电池的太阳能转换性能及其光电转换效率。曲线与横轴相交的点称为开路电压，即在零电流时的最大电压。在0 V时最大电流的点出现在曲线与纵轴相交的位置。最大功率点（MPP）出现在曲线的“拐点”处，对应太阳能电池理想工作状态下的电压和电流条件。通过比较不同太阳能电池的电流-电压曲线的最大功率点，可以评估其性能优劣。本实验测得的开路电压可达0.5伏，短路电流密度为1-2 mA/cm²。染料敏化太阳能电池在特定应用领域具有重要价值，本视频中介绍的方法可实现采用新型染料的电池快速原型制备。由于染料敏化太阳能电池在弱光下能产生较高的功率，因此可用于“光能收集”，即重新利用室内光线为传感器、身份标签、数据发射器等设备供电。实现这一目标的方法之一是开发能够在带隙内引入能级的染料，使电子可从这些能级跃迁至导带。实验表明，通过用两个低能量吸收替代单一的高能量吸收，可在近红外波长范围内使光子到电子的转换效率提高一倍。染料敏化电池可用于生产光伏窗户，其中在电极中添加二氧化钛中空玻璃微球，以减少污染并维持输出性能。对于这种低成本的制造技术，可采用静电纺丝等方法，即将二氧化钛浆料缓慢注入电场中，以制备用于高性能电极的纳米纤维。另一种制造技术是喷墨打印，该方法已被用于在玻璃基底上沉积电极，制得的电池效率可达3.5%。您刚刚观看了 JoVE 关于染料敏化太阳能电池的简介。现在，您应该已经熟悉了染料敏化电池的工作原理、在实验室中低成本制备它们的操作步骤以及一些应用。一如既往，感谢观看！

Education

教育

JoVE Science Education

Chemistry

化学

Inorganic Chemistry

无机化学

dye-sensitized solar cells and light capture

Dye-sensitized solar cells use a dye to capture sunlight and turn it into electrical current. They are a type of solar cell, which is an electrical device that uses light to create current. This approach is modeled on nature, where colored molecules absorb light energy and help drive chemical reactions.

The idea connects to photosynthesis in plants. In leaves, chlorophyll pigments give plants their green color and absorb sunlight to power the conversion of water and carbon dioxide into carbohydrates and oxygen. The same basic principle of light absorption helps explain how DSSCs gather energy from the sun.

The development of solar cells began long before modern devices. In 1839, Edmond Becquerel, a 19-year-old French physicist working in his father’s lab, made the first photovoltaic cell. He exposed an acidic solution of silver chloride connected to platinum electrodes, which produced a voltage and current.

Many discoveries followed in the late 19th century and the first half of the 20th century. The first practical solar cell was built by Bell Laboratories in 1954. From the 1950s onward, solar cells were also used to power satellites in space.

Dye-sensitized solar cells were first invented at UC Berkeley by Brian O’Regan and Michael Grätzel. Grätzel later continued this work at the École Polytechnique Fédérale de Lausanne in Switzerland. Their work led to the first highly efficient DSSC in 1991.

Dye-Sensitized Solar Cells and Light Capture

dye-sensitized-solar-cells-and-light-capture

synthesis of a ti(iii) metallocene using schlenk line technique

synthesis-of-a-tiiii-metallocene-using-schlenk-line-technique

Air-Free Solvent Transfer on a Schlenk Line

Schlenk line technique is a useful way to handle air- and water-sensitive chemicals. In inorganic chemistry, it is often used when compounds must be kept away from oxygen and moisture. This experiment focuses on simple Schlenk line steps, especially solvent preparation and solvent transfer. The procedure shows a new, simple method for degassing solvent, which means removing dissolved gas before use. It also demonstrates how to move solvent by cannula and by syringe on a Schlenk line. These...

glovebox and impurity sensors

Handling Air-Sensitive Samples in a Glovebox

A glovebox lets chemists handle air- and moisture-sensitive solids and liquids inside an inert atmosphere. It is a sealed box with gloves attached to one or more sides. Those gloves let the user work inside the chamber without exposing the sample to air. For inert-atmosphere work, chemists may choose a glovebox, a Schlenk setup, or high-vacuum techniques. Schlenk and especially high-vacuum methods give tighter control over the atmosphere. That makes them useful for reactions that are very...

purification of ferrocene by sublimation

Ferrocene Purification Using Sublimation

Sublimation can be used to purify ferrocene, a solid that turns directly from a solid into a gas. This phase change happens without first becoming a liquid. It occurs at temperatures and pressures lower than the compound's triple point. During sublimation, the solid is heated into the gas phase. Non-volatile impurities stay behind in the sample. The vaporized compound then cools and deposits as a solid on a cold surface. This method works for both organic and inorganic solids. In this...

the evans method

Magnetic Susceptibility in Transition Metal Complexes

Magnetic susceptibility helps reveal whether a transition metal complex has unpaired electrons. Many organic molecules are diamagnetic, which means all of their electrons are paired in bonds. In contrast, many transition metal complexes are paramagnetic and have unpaired electrons in their ground state. Hund's rule says that electrons fill orbitals of similar energy to maximize the number of unpaired electrons before they pair up. Transition metals have partially filled d-orbitals, and ligand...

single crystal and powder x-ray diffraction

single-crystal-and-powder-x-ray-diffraction

X-ray Diffraction for Crystal Structure

X-ray diffraction is used to study the structure of molecules with X-rays. In chemistry, this method is called X-ray crystallography. It is commonly done with either a single crystal or a powdered sample. Single-crystal X-ray diffraction can show the absolute structure of a compound. It reveals the exact positions of atoms, so bond lengths and bond angles can be measured. This method gives the structure inside one crystal, which may not match the bulk of the material. For that reason, other...

electron paramagnetic resonance (epr) spectroscopy

electron-paramagnetic-resonance-epr-spectroscopy

EPR for Studying Antioxidant Behavior

Electron Paramagnetic Resonance (EPR) helps students study unpaired electrons in chemical systems. EPR spectroscopy is used here to examine how dibutylhydroxy toluene, or BHT, acts as an antioxidant during the autoxidation of aliphatic aldehydes. The lesson focuses on the basic principles behind EPR and shows how this method can track radical behavior in a reaction. It also connects the technique to a real chemical example, where BHT is studied for its role in slowing autoxidation. This makes...

m&#246;ssbauer spectroscopy

Ferrocene Analysis by Mössbauer Spectroscopy

Mössbauer spectroscopy is a bulk characterization technique used to study atoms in the solid state. It examines the nuclear excitation of an atom by gamma rays. The method gives a spectrum that can reveal the oxidation state, spin state, and electronic environment around the target atom. These spectral features help build evidence about a molecule’s electronic structure and ligand arrangement, or geometry. The video explains the basic principles behind Mössbauer spectroscopy. It also shows how...

lewis acid-base interaction in ph3p-bh3

Ph3P-BH3 Adduct and Lewis Acids

Chemistry uses models to explain patterns in reactivity, and acid-base definitions have changed over time. Substances have been grouped as acids and bases since ancient Greece. Early descriptions were based on taste. Acids were sour, like lemon juice and vinegar. Bases were used to neutralize acids. The word acid comes from the Latin term for sour-tasting. The word alkaline comes from an Arabic word for roasting, linked to early ash-based bases used to make soap. A later model came from Svante...

structure of ferrocene

Ferrocene Synthesis and Electron Count

Ferrocene synthesis and electron count are the focus of this high school chemistry experiment. Ferrocene is an organometallic compound, which means it contains a metal bonded to carbon-based groups. It was first reported in 1951 by Kealy and Pauson in Nature. The early structure for ferrocene placed the iron atom in a simple sigma bond to one carbon atom on each cyclopentadiene ligand. A later model from Wilkinson and Woodward described a sandwich shape, with iron between two cyclopentadiene...

application of group theory to ir spectroscopy

application-of-group-theory-to-ir-spectroscopy

IR Spectroscopy of Metal Carbonyl Isomers

Infrared spectroscopy of metal carbonyl isomers shows how symmetry can help identify a complex. Metal carbonyl complexes are useful metal precursors for making organometallic complexes and catalysts. IR spectroscopy is one of the most useful ways to study compounds that contain CO groups. Group theory is the use of mathematics to describe molecular symmetry. It can be used to predict how many IR-active C-O vibrational modes a molecule should have. The number of C-O stretches seen in an IR...

molecular orbital (mo) theory

Geometry of Ni and Pd dppf Complexes

Nickel and palladium dppf complexes are the focus of this chemistry protocol. It guides the synthesis of two metal complexes that contain the ligand 1,1'-bis(diphenylphosphino)ferrocene, or dppf. The compounds are M(dppf)Cl2, where M is Ni or Pd. Both metal complexes are four-coordinate, meaning each metal center is bonded to four groups. Even so, they do not share the same geometry at the metal center. Molecular orbital, or MO, theory is used together with 1H NMR and the Evans method to...

quadruply metal-metal bonded paddlewheels

quadruply-metal-metal-bonded-paddlewheels

Synthesizing a Mo2 Quadruple-Bond Complex

Paddlewheel complexes are coordination compounds made from two transition metal ions held close together by four bridging ligands. The metals can come from the 1st, 2nd, or 3rd row of transition metals. The bridging ligands are most often formamidinates or carboxylates. Changing the metal ion or the bridging ligand gives many different paddlewheel complexes. Their close structure allows metal-metal bonding, and that bonding strongly affects how the complexes look and react. Because of this,...

dye-sensitized solar cells

Dye-sensitized solar cells use a dye to capture sunlight and turn it into electrical current. They are a type of solar cell, which is an electrical device that uses light to create current. This approach is modeled on nature, where colored molecules absorb light energy and help drive chemical reactions. The idea connects to photosynthesis in plants. In leaves, chlorophyll pigments give plants their green color and absorb sunlight to power the conversion of water and carbon dioxide into...

synthesis of an oxygen-carrying cobalt(ii) complex

synthesis-of-an-oxygen-carrying-cobaltii-complex

Cobalt Complex Model for Oxygen Binding

Bioinorganic chemistry studies how metals help living systems work. Many proteins contain metals, and some depend on metal-containing active sites to function. Proteins with metals are called metalloproteins. They help carry out important cell functions needed for life. One major role of metalloproteins is oxygen transport. These proteins bind oxygen, move it, and then release it for processes such as respiration. Synthetic inorganic chemists study coordination compounds to model these...

photochemical initiation of radical polymerization reactions

photochemical-initiation-of-radical-polymerization-reactions

Photopolymerizing Styrene Into Polystyrene

Photopolymerizing styrene with light produces polystyrene, a common commodity plastic. This experiment uses simple photochemistry to start a radical polymerization reaction. A radical is a highly reactive particle with an unpaired electron that can help build long polymer chains. The module focuses on benzoyl peroxide as a photo-initiator for styrene polymerization. Benzoyl peroxide absorbs light and helps trigger the reaction. The process also shows how photochemistry can be used to control...

inorganic chemistry

该系列涵盖了一系列无机化学协议和概念, 包括无技术, 过渡金属化合物的合成, 核心无机化学概念, 如路易斯酸和基地, 以及先进的分析技术, 包括EPR 光谱学。

Explore how dye-sensitized solar cells use dyes to absorb sunlight, along with the history of photovoltaic cells and early solar cell breakthroughs.

Dye-Sensitized Solar Cells and Light Capture | JoVE K12

Pennsylvania State Academic Standards

Physical Science

Waves and Electromagnetic Radiation

3.2.9-12.X

Texas Essential Knowledge and Skills

High School

Earth Systems Science

112.49.c.12.

112.49.c.12.E.

new-jersey-student-learning-standards-for-science

New Jersey Student Learning Standards for Science

Energy

HS-PS3-3

Arizona Science Standards

HS.P1

HS.P1U3.4

HS+Phy.P4

HS+Phy.P4U2.7

HS.P4

HS.P4U3.9

HS.P4U1.10

Alabama Course of Study Science

waves-and-their-applications-in-technologies-for-information-transfer

Waves and Their Applications in Technologies for Information Transfer

9-12.PS.2.3.f

Environmental Science

9-12.EVS.4.6.a

Next Generation Science Standards

HS-PS4-5

south-carolina-college-and-career-ready-science-standards

South Carolina College and Career Ready Science Standards

C-PS4-5

Physics

P-PS4-5

Caroline Saouma

Overview

Principles: Band Theory

Principles: Operation of Dye-sensitized Solar Cells

Protocol: Electrode fabrication

Protocol: Cell Construction and Evaluation

Representative Results

Applications

Summary

Threats to Biodiversity

There have been five major extinction events throughout geological history, resulting in the elimination of biodiversity, followed by a rebound of species ...

The Carbon Cycle

Carbon is the basis of all organic matter on Earth, and is recycled through the ecosystem in two primary processes: one in which carbon is exchanged among ...

Energy Dynamics

The Food Chain
Energy is one of the most important abiotic factors in an ecosystem and organisms in an ecosystem are connected by the flow of energy and ...

What is Climate?

Climate refers to the prevailing weather conditions in a specific area over an extended period. As the saying goes, &#8220;Climate is what you expect. ...

Sustainable Development

As the human population continues to grow and use resources, we must be mindful of our planet&rsquo;s natural limits. Sustainable development provides a ...

Global Climate Change

Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global ...

Extinction

The History of Life on Earth
Fossils of organisms that were different from anything alive today had been documented as early as the 17th century, but it ...

Ecological Disturbance

An ecological disturbance is a temporary disruption in the environment resulting from abiotic, biotic, or anthropogenic factors, causing a pronounced ...

Climate Change

The certainty of climate change remains a public controversy despite the consensus among approximately 97% of active climate researchers, who not only ...

Habitat Fragmentation

Habitat fragmentation describes the division of a more extensive, continuous habitat into smaller, discontinuous areas. Human activities such as land ...

Analyze and interpret data to explain the impacts of land use on Earth's systems.

ESS.EES.5.1

water-quality-analysis-via-indicator-organisms

Water Quality Analysis via Indicator Organisms

Source: Laboratories of Dr. Ian Pepper and Dr. Charles Gerba -The University of Arizona
Demonstrating Author: Luisa Ikner
Water quality analysis monitors ...

Nutrients in Aquatic Ecosystems

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
Nitrogen and phosphorus are essential plant nutrients found in aquatic ...

turbidity-and-total-solids-in-surface-water

Turbidity and Total Solids in Surface Water

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
Turbidity and total solids are related measurements addressing clarity of ...

environmental-applications-of-microorganisms

Environmental Applications of Microorganisms

Microorganisms play a pivotal role in maintaining ecosystem balance by recycling essential elements such as carbon, nitrogen, and phosphorus, as well as ...

Dissolved Oxygen in Surface Water

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
Dissolved oxygen (DO) measurements calculate the amount of gaseous oxygen ...

The Water Cycle

The Earth&rsquo;s hydrosphere includes all of the areas where the storage and movement of water occurs. Since water is the basis of all living processes, ...

Biodiversity and Human Values

Human civilization relies on biodiversity in many ways. Sudden changes in species biodiversity result in environmental changes that can modify weather ...

Analyze and interpret data to evaluate how human use of ground and surface waters impacts water quality and availability in river basins, wetlands, estuaries, and aquifers.

ESS.EES.5.2

Measuring Tropospheric Ozone

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
Ozone is a form of elemental oxygen (O3), a molecule of three oxygen atoms ...

determination-of-nox-in-automobile-exhaust-using-uv-vis-spectroscopy

Determination Of NOx in Automobile Exhaust Using UV-VIS Spectroscopy

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
In the troposphere, ozone is naturally formed when sunlight splits nitrogen ...

What is Weather?

Overview

Weather refers to the current state of atmospheric conditions at a specific time and place. Weather is temporary and is influenced by the ...

The Sulfur Cycle

Sulfur, an important element in the chemical makeup of proteins, is recycled through the atmosphere and aquatic and terrestrial environments. Found in the ...

design-example-sustainability-in-concrete-building

Design Example: Sustainability in Concrete Building

A construction firm specializing in concrete buildings constructed a sustainable commercial building.&#160;
The various sustainable practices incorporated ...

The Efficient Level of Pollution

Producing goods often results in pollution as a byproduct, but eliminating all pollution isn&#39;t practical. Doing so would mean halting the production ...

Construct an argument to evaluate the ways that human activities influence atmospheric composition.

ESS.EES.5.3

Proton Exchange Membrane Fuel Cells

Source: Laboratories of Margaret Workman and Kimberly Frye - Depaul University
The United States consumes a large amount of energy &#8211; the current ...

Source: Tamara M. Powers, Department of Chemistry, Texas A&#38;M University
Today&#39;s modern world requires the use of a large amount of energy. While ...

The universe is composed of matter in different forms, and all forms of matter contain energy.&#160; The different forms of energy on Earth originate from ...

Construct an argument to evaluate the benefits and trade-offs of using non-renewable or renewable energy sources for electricity production and transportation fuels.

Proper Waste Disposal

Robert M. Rioux and Taslima A. Zaman, Pennsylvania State University, Pennsylvania, PA

Users are responsible for the proper disposal of the waste ...

Green Marketing

Green marketing is about promoting products or services by highlighting their environmental advantages.
These products or services are produced and ...

The Efficient Amount of Recycling I

In an imaginary town, Greendale, residents carelessly dispose of recyclable plastics due to minimal additional trash pickup fees, leading to recyclable ...

The Efficient Amount of Recycling II

In the town of Greendale, tackling the recyclable plastic waste issue with price or quantity mechanisms, such as a disposal fee, quota, or disposable ...

Bioremediation

Bioremediation is the use of prokaryotes, fungi, or plants to remove pollutants from the environment. This process has been used to remove harmful toxins ...

Construct an argument to evaluate potential solutions that will ensure sustainable consumption of Earth's resources.

ESS.EES.5.5

Community Diversity

Populations do not live in isolation; thus, every population interacts with others in certain ways. These interactions give rise to a network of ...

What is Conservation Biology?

Conservation biology is a scientific field that focuses on the preservation of biodiversity in order to protect ecosystems while meeting the needs of the ...

Construct an argument to evaluate a range of solutions to mitigate impacts of human activities on Earth's systems.

ESS.EES.5.6

Evaluate how human consumption patterns impact Earth's systems.

Dye-Sensitized Solar Cells and Light Capture

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