International Research Fellowship Program: Photocatalytic Water Oxidation by Photosensitization of Nocera's Cobalt Phosphate Catalyst with Modified Ru\(II)\(bpy\) 3 Dyes

0853127 tilley该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。国际研究奖学金项目使美国科学家和工程师能够在国外进行9至24个月的研究。该计划的奖励为联合研究提供了机会，并利用独特或互补的设施、专业知识和国外的实验条件。该奖项将支持Stanley David Tilley博士与Michael Graetzel博士在瑞士洛桑联邦理工学院（Ecole Polytechnique Federale de Lausanne）进行为期24个月的研究。本课题拟研究的重点是水裂解反应(2H2O ？（2H2 + O2），在这个过程中，电子从水中分离出来，形成了一个氧-氧键。在还原半反应中，这些电子被用来将质子还原成氢。利用来自太阳的能量来驱动这一过程，可以将阳光以化学键的形式储存起来，用作燃料。掌握光敏水氧化反应对于利用阳光作为能量输入从水中产生氢燃料的长期目标至关重要。最近发现的Nocera催化剂基于丰富且容易获得的过渡金属钴，能够在中性pH下以1.29V的应用电位分解水以产生氧气。提出的研究旨在通过将光敏染料锚定在钴催化剂上来消除对施加电压的需要。选择无机染料Ru(bpy)32+作为光敏剂，因为Ru3+形式已成功地用作水氧化的化学氧化剂。适当功能化的Ru(bpy)32+染料衍生物将吸附在催化剂表面并起光敏剂的作用。将电子受体系在染料上可以改善电荷分离和从水氧化催化剂中提取电子的效率。然后，电子将被溶液中的可溶性电子受体捕获。该系统的长期目标是将电子传递到生成氢的系统中，尽管目前的提议仅旨在为从水中有效的光催化电子提取奠定基础，因此使用了牺牲电子受体。

0853127TilleyThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).The International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four-month research fellowship by Dr. Stanley David Tilley to work with Dr. Michael Graetzel at the Ecole Polytechnique Federale de Lausanne in Switzerland.The proposed research project focuses on the oxidation half of the water splitting reaction (2H2O ?¨ 2H2 + O2) in which electrons are removed from water and an oxygen-oxygen bond is forged. In the reduction half reaction, these electrons are used to reduce protons to hydrogen. Using energy from the sun to drive the process allows for the storage of sunlight in the form of chemical bonds for use as fuels. The mastery of the photosensitized water oxidation reaction is critical to the long-term goal of generating hydrogen fuel from water using sunlight as the energy input.The recently discovered Nocera catalyst, which is based on the abundant and readily available transition metal cobalt, is capable of splitting water at neutral pH with an applied potential of 1.29V to generate oxygen. The proposed research seeks to eliminate the need for an applied voltage by anchoring a photosensitizing dye to the cobalt catalyst. The inorganic dye Ru(bpy)32+ was chosen as the photosensitizer as the Ru3+ form has been successfully used as a chemical oxidant for water oxidation. An appropriately functionalized Ru(bpy)32+ dye derivative will adsorb to the catalyst surface and function as a photosensitizer. It is expected that tethering an electron acceptor to the dye will improve charge separation and efficiency of electron extraction from the water oxidation catalyst. The electrons will then be captured by a soluble electron acceptor in solution. The long-term goal of this system is to pass the electrons into a hydrogen-generating system, although the current proposal is aimed only at laying the foundation of efficient photocatalyzed electron extraction from water and so uses a sacrificial electron acceptor.