Water splitting photocatalysis with first row transition metal oxides

加州大学戴维斯分校的Frank E.Osterloh教授获得了化学系化学催化项目的这一奖项，他将尝试将廉价而稳定的第一排过渡金属氧化物转化为有效的光催化剂，将水分解为氧气和氢燃料。尽管许多已知的材料强烈地吸收可见光，但由于光化学载流子寿命短，电荷传输缓慢，以及水还原或氧化的巨大过电位，它们没有被用于光化学分解水。在这项研究中，这些问题将通过对材料进行纳米级处理，并通过使用提高反应性的化学过程来修改颗粒表面来解决。将对纳米金属氧化物进行先进的测量，以获得对颗粒大小、电子性质和光催化活性之间关系的新见解。长期以来，水的分解反应一直被认为是从太阳能中产生燃料的一种可能方法。在这里，光被用来激励材料产生光伏。然后，该电压可用于将水电解(裂解)为氢和氧。氢是一种能量丰富的分子，可以作为一种多功能燃料用于运输，或发电和其他高价值的化学品。由于阳光被用作制造氢气的能源，因此不会耗尽化石燃料，也不会产生会导致气候变化的二氧化碳。今天，太阳能水的分解受到缺乏具有所需的反应性和吸收可见光的材料的限制，这些材料的化学稳定、丰富和足够便宜，足以大规模应用这项技术。该项目将尝试开发过渡金属氧化物作为该过程的催化剂。这些氧化物已被证明结合了几种很有前途的性质，而且它们价格低廉，储量丰富。研究生和本科生将参与该项目的各个方面。这些学生将接受太阳能转换和材料科学方面的培训。还将开展化学演示，教育公众太阳能转换的重要性。

With this award from the Chemical Catalysis Program of the Division of Chemistry, Professor Frank E. Osterloh from the University of California at Davis will attempt to convert inexpensive and stable first row transition metal oxides into effective photocatalysts for splitting water into oxygen and hydrogen fuel. Even though many known materials absorb visible light strongly, they are not being utilized for photochemical water splitting because photochemical charge carriers are short lived, charge transport is slow, and because of large overpotentials for water reduction or oxidation. In this research these problems will be addressed by nanoscaling the materials and by modifying the surfaces of the particles using chemical processes that will improve reactivity. Advanced measurements on the nano-metal oxides will be conducted to obtain new insight into the relationship between particle size, electronic properties, and photocatalytic activity. The water splitting reaction has long been considered as a possible method to generate fuel from solar energy. Here, light is used to excite a material to produce a photovoltage. That voltage can then be used to electrolyze (cleave) water into hydrogen and oxygen. Hydrogen is an energy-rich molecule that can serve as a versatile fuel for transportation, or to generate electricity and other high value chemicals. Because sunlight is used as energy source for making the hydrogen, no fossil fuels are used up and no carbon dioxide is produced that would contribute to climate change. Today, solar water splitting is limited by the lack of materials that have the desired reactivity and absorb visible light, and that are chemically stable, abundant, and cheap enough for large scale application of this technology. This project will attempt to develop transition metal oxides as catalysts for the process. These oxides have been shown to combine several promising properties, and they are cheap and abundant. Graduate and undergraduate students will be involved in all aspects of the project. The students will receive training in solar energy conversion and materials science. Chemical demonstrations will also be developed to educate the public about the importance of solar energy conversion.