Collaborative Research: Dye Molecule-Anchored Platinum Nanocatalysts

合作研究：染料分子锚定的铂纳米催化剂低成本太阳能转换最深入研究的系统之一是染料敏化太阳能电池（DSSC），其中附着在纳米颗粒半导体上的染料分子吸收阳光并将电子注入半导体。电子可以被提取并用于电力，但在染料可以重复循环之前，它的电子必须通过与溶解的氧化还原对反应而被取代。这种氧化还原对的一种选择是结合碘离子和三碘离子，这两种离子都非常便宜和丰富。碘离子/三碘离子对几乎是理想的，但有一个问题：电子在从这些离子转移到染料时损失了大量的能量。该项目旨在通过将纳米尺寸的催化剂精确定位在染料与碘化物/三碘化物反应的位置来减少能量损失。该奖项是为了表彰亚历山大G.康涅狄格大学的Agrios，提供纳米颗粒合成和DSSC器件制造和测量方面的专业知识，罗格斯大学的Elena Galoppini教授？纽瓦克，为合成的专业知识，是从以前的EAGER奖的研究人员。这项工作有可能将DSSC的太阳能转换效率提高50%，同时保留廉价的氧化还原对。此外，使用分子设计将催化金属纳米颗粒直接拴系到电化学反应位点的概念可以应用于其他类型的可再生能源项目，例如光催化系统。这项研究将结合推广工作，其中太阳能电池将被用作教学工具在K？12教育解释化学，工程和能源的概念，激发和激励下一代STEM学生和研究人员。这些活动将针对代表性不足的群体，包括来自纽瓦克市区的高中生，也是通过ACS项目SEED方案。该项目利用特制的染料分子，在分子的相对两侧具有两个不同的连接基团。一个基团（羧酸）附着在金属氧化物如二氧化钛（TiO 2）的表面。另一个基团（硫杂环戊烷）连接到某些金属，并将在这里用于锚铂纳米颗粒（Pt NP）。该项目有三个主要的智力组成部分。首先，制造TiO 2-染料-催化剂组件将需要（a）制备所需Pt NP，（B）合成专用染料分子，和（c）组装组分以得到所需结构。第二，组织能力？分子整流将在其与Pt NP的连接点处被掺入染料中，以确保电子根据需要从Pt NP转移到染料，而不是以相反的方向转移，这将使器件短路并降低其太阳能转换效率。第三，染料分子中的电子能级将通过结构修饰调整到将以最小的能量损失在所需方向上提供快速电子转移的值。

Collaborative Research: Dye Molecule-Anchored Platinum NanocatalystsOne of the most intensely studied systems for low-cost solar energy conversion is the dye-sensitized solar cell (DSSC), in which a dye molecule attached to a nanoparticulate semiconductor absorbs sunlight and injects an electron into the semiconductor. The electron can be extracted and used for electrical power, but before the dye can repeat the cycle, its electron must be replaced by reaction with a dissolved redox couple. One option for this redox couple combines iodide and triiodide ions, both of which are extremely cheap and abundant. The iodide/triiodide couple is nearly ideal for this purpose but for one problem: electrons lose a significant amount of energy while transferring from these ions to the dye. This project aims to reduce that energy loss by positioning a nano-sized catalyst precisely at the site where the dye reacts with the iodide/triiodide. The award is for a collaboration between Prof. Alexander G. Agrios at the University of Connecticut, providing expertise in nanoparticle synthesis and DSSC device fabrication and measurement, and Prof. Elena Galoppini at Rutgers University?Newark, for the synthesis expertise, and is derived from a previous EAGER award to the investigators. The work has the potential to increase the solar power conversion efficiency of the DSSC by as much as 50% while retaining the cheap redox couple. In addition, the concept of tethering catalytic metal nanoparticles directly to the site of an electrochemical reaction using molecular design can be applied to other kinds of renewable energy projects, such as photocatalytic systems. The research will be coupled to outreach efforts in which solar cells will be used as a teaching tool in K?12 education to explain concepts of chemistry, engineering and energy and to excite and inspire the next generation of STEM students and researchers. These activities will target underrepresented groups including high-school students from the Newark urban area, also through the ACS project SEED program. This project makes use of specially made dye molecules with two different attachment groups on opposite sides of the molecule. One group (a carboxylic acid) attaches to the surface of metal oxides such as titanium dioxide (TiO2). The other group (a thiolane) attaches to certain metals, and will be used here to anchor platinum nanoparticles (Pt NPs). The project has three main intellectual components. First, fabricating the TiO2-dye-catalyst assembly will require (a) preparing the desired Pt NPs, (b) synthesizing the specialized dye molecule, and (c) assembling the components to give the desired structure. Second, groups capable of ?molecular rectification? will be incorporated into the dye at its point of connection to the Pt NP to ensure that electrons transfer from the Pt NP to the dye, as desired, and not in the reverse direction, which would short-circuit the device and reduce its solar power conversion efficiency. Third, electron energy levels in the dye molecule will be tuned by structural modification to the values that will give rapid electron transfer in the desired direction with minimal energy loss.