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奖项，他将尝试将廉价且稳定的第一行过渡金属氧化物转化为有效的光催化剂，用于将水分解为氧气和氢燃料。尽管许多已知的材料强烈吸收可见光，但由于光化学载流子寿命短，电荷传输缓慢，并且由于水还原或氧化的过电位大，它们没有被用于光化学水分解。在这项研究中，这些问题将通过纳米化材料和使用化学过程修改颗粒表面来改善反应性来解决。将对纳米金属氧化物进行先进的测量，以获得粒径、电子性质和光催化活性之间关系的新见解。水裂解反应一直被认为是利用太阳能生产燃料的一种可能方法。在这里，光被用来激发一种材料来产生光电压。这个电压可以用来将水电解（裂解）成氢和氧。氢是一种能量丰富的分子，可以作为交通运输的多功能燃料，或发电和其他高价值化学品。由于太阳能被用作制造氢气的能源，因此不会消耗化石燃料，也不会产生导致气候变化的二氧化碳。目前，太阳能水分解技术由于缺乏具有理想反应性和吸收可见光的材料而受到限制，这些材料在化学上是稳定的，丰富的，并且足够便宜，无法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有前途的特性，而且它们既便宜又丰富。研究生和本科生将参与项目的各个方面。学生们将接受太阳能转换和材料科学方面的培训。还将进行化学演示，以教育公众了解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.