CAREER: Rational Design, Synthesis and Understanding of Heteronanostructures as Photoelectrodes for Water Splitting

先进的能量转换装置的性能，包括太阳能水分解装置的性能，最终与纳米级电极材料的设计有关。 目前在这一领域的研究受到限制的程度，可以定制现有材料的固有特性和发现新材料的进展缓慢。 在材料研究部的固态和材料化学计划的支持下，该提案将通过设计，制备和理解一类新的纳米材料来应对挑战。 该项目将建立在PI过去成功制造具有异质界面的纳米结构的基础上，通过研究包括TiSi 2纳米网的组合，TiSi 2纳米网是PI实验室发现的独特的二维纳米结构，提供适当的高表面积和高电导率，以及各种氧化物半导体，如TiO 2，WO 3和Fe 2 O 3。 具体而言，PI旨在解决这些氧化物内的电荷扩散不良的问题。 改进的电荷收集将减少光生电荷的不期望的积累，从而增加光子到电子转换效率。 该研究将侧重于了解纳米结构的电子特性如何受到其形态和成分的影响。 采用的实验技术包括化学气相沉积（用于创建TiSi 2纳米网），原子层沉积（用于纳米网周围的氧化物半导体的保形涂层），各种电化学方法和大量的结构表征程序。 这些实验将产生有关纳米结构的结晶度、电子性质和化学性质的信息，这些信息不仅对水分解至关重要，而且对许多相关的能量转换和储存过程也至关重要，其中电荷传输起着重要作用。非技术总结：收集太阳能并直接利用它通过分解水产生氢气的能力有可能满足能源需求，而不会对环境产生负面影响。 由于缺乏合适的材料，这项研究目前进展缓慢。 拟议的项目将引入一种全新的设计，可能会显着推进该领域，并使太阳能水分解实用。 这个设计的关键是PI实验室发现的独特的二维纳米网结构。 当与氧化物半导体结合时，纳米网可以提供专用的电荷传输路径，从而实现高效的太阳能水分解。 研究工作将通过一个旨在传播清洁能源技术信息的完全综合的新教育计划得到加强。 该推广计划将利用波士顿学院足球赛的受欢迎程度。 PI的团队将参加FanFest活动，该活动吸引了大量的校友和游客，包括K-12学生，通过展示如何生产和使用清洁能源。 此外，还将设立一个暑期项目，每年邀请一到两名当地高中的科学教师就拟议的课题进行研究，并获得实践经验，他们将能够与学生分享。

TECHNICAL SUMMARY:The performance of advanced energy conversion devices, including that for solar water splitting, is ultimately connected to the design of the electrode materials at the nanoscale. Current research in this area is limited by how much one can tailor the intrinsic properties of existing materials and the slow progress in discovering novel materials. Supported by the Solid State and Materials Chemistry program within the Division of Materials Research, this proposal will address the challenge by designing, preparing and understanding a new class of nanonet-based materials. The project will build on the PI's past success in making nanostructures with heterogeneous interfaces by studying combinations that include TiSi2 nanonets, which are unique two-dimensional nanostructures discovered by the PI's lab that offer suitably high surface areas and high conductivities, and a variety of oxide semiconductors such as TiO2, WO3 and Fe2O3. Specifically, the PI aims at solving the problems of poor charge diffusion within these oxides. The improved charge collection will reduce the undesired accumulation of photogenerated charges and thereby increase the photon-to-electron-conversion efficiencies. The study will focus on understanding how the electronic properties of nanostructures are influenced by their morphologies and compositions. Experimental techniques to be employed include chemical vapor deposition (for the creation of TiSi2 nanonets), atomic layer deposition (for the conformal coating of oxide semiconductors around the nanonets), various electrochemical methods, and a host of structural characterization procedures. These experiments will produce information on the crystallinity, the electronic property and the chemical property of the nanostructures, which will be essential to not only water splitting but also a number of related energy conversion and storage processes where charge transport plays an important role.NON-TECHNICAL SUMMARY:The ability to harvest solar energy and use it directly to produce hydrogen by splitting water has the potential to meet the energy needs without a negative impact on the environment. Due to the lack of suitable materials, this research is currently progressing at a slow pace. The proposed project will introduce a fundamentally new design that may advance the field significantly and make solar water splitting practical. The key to this design is a unique two-dimensional nanonet structure the PI's lab has discovered. When combined with oxide semiconductors, the nanonets can provide a dedicated charge transport pathway that should enable high-efficiency solar water splitting. The research efforts will be augmented by a fully integrated novel education program that aims at disseminating information on clean energy technology. The outreach program will take advantage of the popularity of Boston College's football games. The PI's team will participate in the FanFest event, which attracts a large number of alumni and visitors including K-12 students, by demonstrating how clean energy can be produced and used. A summer program will also be established to invite one to two science teachers each year from local high schools to conduct research on the proposed topics and gain hands-on experience which they will be able to share with their students.