Highly Robust and Efficient Water Oxidation Catalysts based on Nanoscopic Metal Oxide Species (Polyoxometalates): from Fundamental Science to Devices

在这个SPP中，光解电池被开发出来，可以收集阳光并利用这些能量分解水。水裂解发生在两个半反应中，即析氢反应和析氧反应（HER和OER）。每个电子过程只需要1.23 eV来分解水，高效的光收集材料将提供1.8…2.5 eV的电池电压，具体取决于。由于与HER和OER相关的屏障会抑制反应并大大降低整体电池效率，因此开发高选择性效率、低成本且无环境问题的催化剂非常重要。我们建议在多金属氧酸盐（pom）的基础上开发新的OER催化剂。在过去的三年中，新兴的纳米级聚甲醛显示出作为水裂解催化剂的巨大潜力。在溶剂化的金属离子和扩展的金属氧化物晶格之间，这些独特的金属氧化物团簇可用于不同拓扑结构的催化核心的整合和工程。目前的文献表明，基于POM的光催化水氧化系统在可见光区域的量子效率高达30%，周转频率约为450 h-1。然而，我们相信更高效的Ru-POM催化剂以及基于更丰富和负担得起的金属（例如Mn， Co, Ni）的POM水氧化催化剂可以被开发出来。除了效率高之外，POMs还有几个强大的特点，即簇可以在中性和低ph下工作，具有热稳定性和氧化稳定性，可以结合成本效益和环境友好的元素，并且可以在半导体表面上固定。在本提案中，我们提出开发高效的Ru POM催化剂，并探索基于较便宜金属（Mn, Co, Ni）的POM的潜力，以驱动OER。我们将合成并彻底表征这些材料，并在均相中测试其催化性能，最后将其沉积到TiO2上以制备光电催化阳极。发展是实验和理论之间的密切合作，有四个相互关联的理论和实验研究包。

In this SPP, photoelectrolytic cells are developed that harvest sunlight and use that energy to split water. The water splitting occurs in two half-reactions, the hydrogen and the oxygen evolution reactions (HER and OER). Only 1.23 eV per electron process are necessary to split water, highly 2 efficient light-harvesting materials will deliver cell voltages of 1.8…2.5 eV, depending. As a barrier is associated to HER and OER that suppresses the reaction and considerably lowers the overall cell efficiency, it is important to develop catalysts of high selective efficiency, low cost, and without environmental issues. We propose to develop novel catalysts for the OER on the basis of polyoxometalates (POMs).The emerging class of nanoscopic POMs in the past three years revealed significant potential as water splitting catalysts. Ranging between solvated metal ions and extended metal oxide lattices, these unique metal-oxide clusters are available for incorporation and engineering of catalytic cores with varying topologies. Current literature reveals high quantum efficiency for POM based photocatalytic water oxidation systems of up to 30% in the visible light region and turnover frequencies of about 450 h-1. However we believe that even more efficient Ru-POM catalysts as well as POM water oxidation catalysts based on more abundant and affordable metals (e.g. Mn, Co, Ni) can be developed. Besides their high efficiency, POMs have several strong features, namely the clusters can operate in neutral as well as low pHs, are thermally and oxidatively stable, can incorporate cost efficient and environmentally friendly elements and they are compatible for immobilization on semiconducting surfaces.In this proposal we offer to develop highly efficient Ru POM catalysts as well as explore the potential of POMs based on the less expensive metals (Mn, Co, Ni) for driving the OER. We will synthesize and thoroughly characterize these materials, test their catalytic performance in homogeneous phase and finally deposit them to TiO2 in order to produce photoelectrocatalytic anodes. The developments are a close collaboration between experiment and theory, with four mutually interconnected theoretical and experimental research packages.