3-D Nanowire Heterostructures from Earth Abundant Materials by Low-cost Fabrication Process for High-efficiency Photoelectrochemical Hydrogen Generation

Pi：Wang，Deli Proposal编号：1236155机构：加州大学圣迭戈分校标题：D纳米线地球异质结构高效光电化学氢气的低成本制造工艺丰富的材料阳光和海水是地球上最终的可持续能源。它们共同构成了全球能源危机的潜在解决方案，同时可以减少因使用化石燃料而产生的碳排放。光电化学(PEC)电池利用太阳能直接分解水并产生氢气，这是清洁的，没有碳排放。然而，PEC社区广泛认识到，在光吸收、水分减少、化学稳定性等方面，没有一种单一的材料可以成为完美的太阳能水分解候选材料。本项目将研究使用三维(3D)树状分枝纳米线异质结构作为光电电极，通过低成本的制造工艺从地球上丰富的材料中获得高效和潜在的、实用和可持续的清洁氢气产生。树状三维分枝纳米线阵列提供了对高效PEC制氢至关重要的所需特性的独特组合，包括增强的光吸收、改进的电荷分离/收集、更大的表面积和更好的电化学反应动力学。具体地说，建议的研究重点将是：(1)利用富含稀土的材料(Si、Cu2O、Fe2O等)设计和制备三维纳米结构光电极。通过低成本的溶液工艺，(Ii)了解纳米线核心和分支之间的界面及其对光生载流子分离和传输的影响，以及(Iii)了解电解液/纳米线界面，特别是半导体电极在高局部酸性/碱性条件下的表面电化学反应/腐蚀。此外，还将研究具有化学稳定性的材料，如二氧化钛和三氧化二钨。这项研究将加深对有关纳米材料和界面中异质结形成的基本材料科学和化学问题的理解，并创建一种在纳米尺度上进行异质功能集成的新范式。具体地说，在可再生能源研究方面，这项工作还将为高效光伏器件和氢气发电的设计和制造提供帮助。此外，该项目将为本科生和研究生提供与该项目相关的跨学科领域的培训机会。

PI: Wang, DeliProposal Number: 1236155Institution: University of California-San DiegoTitle: D Nanowire Heterostructures from Earth Abundant Materials by Low-cost Fabrication Process for High-efficiency Photoelectrochemical Hydrogen GenerationSunlight and seawater are the ultimate sustainable energy sources on earth. Together they constitute a potential solution to the global energy crisis and at the same time can reduce carbon emission due to the use of fossil fuels. A photoelectrochemical (PEC) cell utilizes solar energy to directly split water and generate hydrogen, which is clean and free of carbon emission. However, it is broadly recognized by the PEC community that there is no single material that can be the perfect photoelectrode candidate for solar water splitting with respect to light absorption, water reduction, chemical stability, etc. This project will investigate the use of three-dimensional (3-D) tree-like branched nanowire heterostructures from earth abundant materials by low-cost fabrication process as photoelectrodes for high efficiency and potentially, a practical and sustainable clean hydrogen generation. The array of the tree-like 3-D branched nanowires offers a unique combination of desired properties that are critical to high efficiency PEC hydrogen generation, including enhanced light absorption, improved charge separation/collection, enlarged surface area, and better electrochemical reaction dynamics. Specifically, the proposed research focus will be on (i) design and fabrication of the 3-D nanostructured photoelectrodes using earth abundant materials (Si, Cu2O, Fe2O3, etc.) by low-cost solution processes, (ii) understanding of the interface between the nanowire core and branches and their effect on separation and transport of the photogenerated charge carriers, and (iii) understanding of the electrolyte/nanowire interface, in particular the surface electrochemical reaction/corrosion of semiconductor electrodes at high local acidic/basic conditions. Chemically robust materials such as TiO2 and WO3 will also be studied. The research will develop an understanding of the fundamental materials science and chemistry questions regarding heterojunctions formation in nanomaterials and interfaces, as well as create a new paradigm of heterogeneous functional integration at nanoscale. Specifically with regard to renewable energy research, this work will also shine a light on design and fabrication/manufacturing of high-efficiency photovoltaic devices and H2 generation. In addition, the project will provide opportunity to the undergraduate and graduate students to obtain training in the interdisciplinary areas related to this project.