Electrode and Catalytic Materials for Solar Light Harvesting and Fuel Generation Systems

对气候变化的日益关注要求我们以对环境负责的方式开发新的能源。已经开发了由太阳能、电化学过程、催化或其组合驱动的原型燃料产生装置。然而，需要在成本、可扩展性、长期稳定性和性能方面进一步优化，才能继续将这些方法扩展到现有和新兴的能源基础设施。建议的研究计划包括合理设计用于太阳光吸收以及二氧化碳和氮气还原反应的电极材料和电催化剂。这些目标将在三个主题下实现： 主题1：作为光电极的铜和铁基纳米线阵列。寻找价格低廉、稳定无毒、具有特殊光电性能的太阳能吸收材料的努力一直不太成功。纳米线阵列是传统单晶或薄膜太阳能吸光器的一种可行的替代方案，因为纳米线的几何形状允许更少的材料使用、增强的光捕获、高效的载流子收集，并实现机械灵活性。由铜、铁氧化物和硫化物组成的地球上丰富而廉价的金属硫化物纳米线阵列及其表面化学将被开发用于太阳能转换器件的光吸收。 主题2：用于二氧化碳还原反应的催化剂的开发和与光电极的集成。通过将二氧化碳转化为附加值材料来缓解二氧化碳浓度增加的影响是一个有吸引力和前景的解决方案。然而，需要开发高活性、高稳定性和高选择性的催化剂，以便高效、经济地将二氧化碳转化为附加值材料。将合成由Ni、Fe、Co、Ga合金组成的纳米颗粒电催化剂，并将其应用于二氧化碳还原。它们将被进一步集成到纳米线阵列中，以制造性能最佳的太阳能驱动的二氧化碳转化设备。 主题3.作为氮气还原电极材料的金属氮化物。金属氮化物是一种坚固的材料，具有优异的机械和化学稳定性，可以在催化反应中取代高成本和有限供应的贵金属。开发高比表面积的金属氮化物，并将其应用于电化学氮气还原反应合成氨。将进行原位拉曼光谱研究，以基本了解氮在金属氮化物表面的反应性。 拟议的研究对加拿大很重要，因为它将允许设计不含贵金属和无毒的性能更高的材料。拟议的研究计划将培养在材料合成、表征以及材料在能源、可持续化学和催化过程中的应用方面的高素质人才。

Increasing concerns over climate change require us to develop new sources of energy in an environmentally responsible fashion. Prototypical fuel generation devices driven by solar, electrochemical processes, catalysis, or combinations thereof have been developed. However, further optimization is required in terms of cost, scalability, long term stability, and performance for continued expansion of these methodologies into existing and emerging energy infrastructure. The proposed research program involves the rational design of electrode materials and electrocatalysts for solar light absorption and CO2 and N2 reduction reactions. These goals will be pursued under three themes: Theme 1: Cu and Fe based nanowire arrays as photoelectrodes. The quest for solar absorber materials with exceptional optoelectronic properties that are inexpensive, stable, and non-toxic has been less than successful. Nanowire arrays are a viable alternative to traditional single-crystal or thin film solar light absorbers, as the wire geometry allows for less material usage, enhanced light trapping, efficient carrier collection, and enables mechanical flexibility. Earth abundant and inexpensive metal chalcogenide nanowire arrays made of Cu and Fe oxides and sulfides and their surface chemistry will be developed for light absorption in solar energy conversion devices. Theme 2: Catalyst development and integration with photoelectrodes for CO2 reduction reactions. Mitigating the effects of increasing CO2 concentration by converting it to value added materials is an attractive and promising solution. However, catalysts with high activity, stability, and selectivity need to be developed for efficient and cost effective conversion of CO2 into value added materials. Nanoparticle electrocatalysts composed of Ni, Fe, Co, and Ga alloys will be synthesized and applied towards CO2 reduction. They will be further integrated into nanowire arrays to fabricate optimally performing solar driven CO2 conversion devices. Theme 3. Metal nitrides as electrode materials for N2 reduction. Metal nitrides are robust materials that exhibit exceptional mechanical and chemical stability, and could replace noble metals of high cost and limited supply in catalytic reactions. High surface area metal nitrides will be developed and applied towards electrochemical N2 reduction reactions to synthesize ammonia. In-situ Raman spectroscopy studies will be done to gain fundamental understanding of N2 reactivity on metal nitride surfaces. The proposed research is of importance to Canada as it will allow for the design of materials of increased performance that are free of precious metals and are non-toxic. The proposed research program will train highly qualified personnel with skill sets in material synthesis, characterization, and the applications of materials in energy, sustainable chemistry, and catalytic processes.