CAREER: Developing Novel Biomimetic Heterostructured Ceramics for Water Splitting

非技术描述：将太阳能转化为燃料的新方法的发展为解决可持续能源和环境问题提供了巨大的潜力。利用阳光和光活化材料从水中生产氢气是太阳能储存和转换的一个有吸引力的策略。尽管在新材料的设计上取得了巨大的进步，但这种转换过程的效率仍然很低。为了应对这一挑战，该项目专注于通过采用生物系统中自然发生的过程来克服材料科学和化学中的几个瓶颈。实验策略使用了新型复合材料，其中氧和氢是在不同的半导体耦合在一起产生的。这种受自然光合作用启发的方法被称为z型方案。技术描述：先前的研究采用z方案进行水分解，通常涉及在水溶液中使用两种不同的半导体粉末，它们通过氧化还原剂偶联，作为两种成分之间的电子穿梭。在这项工作中，Orlov的团队正在使用全固态z方案系统，该系统具有使用单个组分的潜在优势，这些组分仅针对水分解半反应（水氧化或水还原）中的一种进行了优化，并将它们紧密接触以促进它们之间的电荷转移。通过消除对氧化还原穿梭的需要，全固态z型光催化剂提供了更高效率的潜力，并且更适合使用表面科学探针进行原子和电子结构的基础研究。具体来说，实验设计涉及到结合两种金属氧化物材料的系统，这两种金属氧化物材料作为氧化和还原光催化剂，既可以制备成粉末，也可以制备成具有明确表面特性的薄膜。这项研究的转型方面是开发一种新型复合系统，与任何单一催化剂相比，它具有更高的产氢活性。模型光催化剂的开发和表征提出了许多挑战，本项目通过广泛的表征技术、固态合成、活性表征和表面科学工具的跨学科方法来解决这些挑战。与项目相关的活动还扩展了材料科学和工程领域的课程和前沿研究机会，并大量纳入了代表性不足的学生。此外，该计划的教育部分还利用他们新开发的光催化测试工具，向高中学生和教师介绍纳米技术研究。该项目还包括其他一些创新元素，例如开发旨在向学生传授可持续材料概念的在线教育工具。

NON-TECHICAL DESCRIPTION: Development of new methods for converting solar energy into fuels offers tremendous potential to address both sustainable energy and environmental issues. Producing hydrogen from water using sunlight and light-activated materials is an attractive strategy for solar energy storage and conversion. Despite tremendous progress in the design of new materials, the efficiency of this conversion process is still very low. To address this challenge, this project focuses on overcoming several bottlenecks in materials science and chemistry by adopting a process that occurs naturally in biological systems. The experimental strategy uses novel composite materials, where oxygen and hydrogen are produced on different semiconductors coupled together. This approach, inspired by natural photosynthesis, is called the Z-scheme.TECHNICAL DESCRIPTION: Previous studies employing a Z-scheme for water splitting typically involved the use of two different semiconductor powders in aqueous solutions, which are coupled by redox agents that act as an electron shuttle between the two components. In this work, Orlov's group is using an all solid-state Z-scheme system which has the potential advantage of using individual components that are optimized for only one of the water splitting half reactions (water oxidation or water reduction), and placing them in intimate contact to promote charge transfer between them. By eliminating the need for a redox shuttle, an all solid-state Z-scheme photocatalyst offers the potential of higher efficiency and is more amenable to fundamental investigations of atomic and electronic structure using surface science probes. Specifically, the experimental design involves working with systems that combine two metal oxide materials that act as oxidation and reduction photocatalysts that can be prepared both as a powder and as a thin film with well-defined surface properties. The transformational aspect of this research is in development of a new class of composite systems with potentially higher activity for hydrogen production as compared to any single catalyst. The development and characterization of the model photocatalyst presents many challenges, which this project addresses by an interdisciplinary approach with broad range of characterization techniques, solid-state synthesis, activity characterization and surface science tools. The project-related activities also expand the curriculum and cutting edge research opportunities in materials science and engineering with significant inclusion of underrepresented students. In addition, the educational part of the project introduces high school students and teachers to nanotechnology research using their newly developed photocatalytic testing kit. The project also includes several other innovative elements, such as the development of on-line educational tools designed to teach students the concepts of sustainable materials.