EAGER: Collaborative Research: Dye-anchored nanocatalysts for improved solar energy conversion efficiency

染料敏化太阳能电池（DSSC）是一种非常有前途的低成本太阳能发电技术。该装置有三个基本组成部分：一层宽带隙半导体（纳米TiO2）薄膜沉积在透明导电玻璃电极上并涂有染料；镀了铂的对电极；以及含有碘化物/三碘化物氧化还原对的电解质溶液。然而，由于驱动关键染料再生反应所需的高电化学过电位（约0.5 V），电池效率受到限制，在该反应中，碘化物使氧化染料分子与TiO2纳米颗粒结合，生成三碘化物和未带电的染料作为产物。来自康涅狄格州斯托尔斯市康涅狄格大学的Alex Agrios教授和新泽西州纽瓦克市罗格斯大学的Elena Galoppini教授提议将催化Pt纳米颗粒附着在固定在TiO2表面的染料分子上。他们假设，与染料分子结合的铂可以催化染料再生，通过能量较低的中间体进行反应，并大大减少氧化染料和碘化物之间所需的过电位。这项工作将利用催化来消除低成本染料敏化太阳能电池能量转换效率的长期限制。这项合作的EAGER提案包括进行初步合成的实验和验证主要假设的实验，以证明纳米催化剂提高DSSC太阳能转换效率的可能性。由于驱动电池的电化学过程中的能量损失，每个电子空穴对的电化学能量约有一半损失。人们普遍认为，DSSC研究的下一个突破将是恢复这些损失的能量。这项工作的意义将是实用的和基础的，分子锚定纳米催化剂的概念在各个领域都有潜在的影响。

Dye-sensitized solar cells (DSSC) are a very promising technology for low-cost conversion of solar energy to electricity. The device has three essential components: a wide-bandgap semiconductor (nanocrystalline TiO2) film deposited on a transparent conducting glass electrode and coated with a dye; a platinized counterelectrode; and an electrolyte solution containing the iodide/triiodide redox couple. However, cell efficiencies have been limited due largely to the high electrochemical overpotential (about 0.5 V) needed to drive the critical dye regeneration reaction, where iodide reduces an oxidized dye molecule bound to a TiO2 nanoparticle, yielding triiodide and the uncharged dye as products. The PIs, Professors Alex Agrios of the University of Connecticut, Storrs, CT, and Elena Galoppini of Rutgers University, Newark, NJ, propose to attach catalytic Pt nanoparticles to the dye molecules anchored to the TiO2 surfaces. They hypothesize that Pt bound to the dye molecule can catalyze dye regeneration, routing the reaction through less energetic intermediates and greatly reducing the overpotential required between oxidized dye and iodide. This work will employ catalysis to remove a longstanding limitation on the energy conversion efficiency of low-cost dye-sensitized solar cells.This collaborative EAGER proposal covers experiments to carry out the initial syntheses and experiments to test the main hypothesis to demonstrate the possibility of nanocatalysts to improve DSSC solar energy conversion efficiency. About half of the electrochemical energy of each electron hole pair is lost due to energy losses in the electrochemical processes driving the cell. It is generally acknowledged that the next breakthrough in DSSC research will be the recovery of this lost energy. The significance of this work will be both practical and fundamental, with the concept of molecularly anchored nanocatalysts having potential implications in diverse fields.