Photocatalysis with Ferroelectric Light Absorbers

铁电光吸收器的光催化

• 批准号: 1900136
• 负责人: Frank Osterloh
• 金额: $ 48.5万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2023-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1900136&HistoricalAwards=false
• 关键词: Photocatalysis; Ferroelectric; Light; Absorbers

Photocatalysis with Ferroelectric Light AbsorbersReplacing polluting fossil fuels with clean alternatives is one of the grand challenges of the modern world. A more sustainable energy economy may be achievable with photocatalysts that can produce hydrogen fuel from water, using sunlight as the only energy input. Hydrogen is regarded as a "green" fuel because it releases its stored energy by re-forming water. A problem of known photocatalysts is that their energy conversion efficiency is low, that is, they absorb a lot of energy from sunlight but only some of this energy is converted to a usable fuel. This project studies the use of "ferroelectric" light absorbers to increase the energy conversion efficiency. The new ferroelectric light absorbing materials are studied using microscopic, optical, electrical, and chemical methods. The research is conducted by a postdoctoral associate and by graduate students. All team members are trained in the preparation of the materials and in the application of modern instruments and techniques for their characterization. New internship positions for undergraduate students from underrepresented groups are also created. Chemistry shows at local schools and on campus motivate children to study the natural sciences, tackling important societal problems like clean energy. Experimental demonstrations are distributed as online materials to educate the public about sustainable fuel research.With funding from the Chemical Catalysis Program of the Chemistry Division, Dr. Osterloh of the University of California, Davis, is studying ferroelectric effects in a set of photocatalyst materials derived from the perovskites M:ATiO3. Here, A is an earth alkaline element and M is a transition metal ion. These materials are relevant to the development of third generation photovoltaic devices and photocatalysts for the production of sustainable energy. The compounds are synthesized with solid state and hydrothermal methods from abundant elements, and they are characterized with electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and UV/vis spectroscopy. Site-selective modification with water oxidation and reduction co-catalysts is applied to fabricate ferroelectric photocatalysts for the overall water splitting reaction. A combination of dielectric polarization experiments, surface photovoltage spectroscopy, photocatalytic, and electrochemical measurements is used to determine the extent to which ferroelectric dipoles can enhance photochemical energy to fuel conversion with these materials. Additionally, the project trains graduate, postgraduate and undergraduate students in the preparation of inorganic materials and advanced methods for characterizing their morphology, structure and photochemistry. Outreach events are conducted to engage and motivate the next generation of STEM students for research in catalysis. Online materials are disseminated to educate the public about sustainable energy production.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

铁电光吸收剂的光催化用清洁的替代品取代污染的化石燃料是现代世界的重大挑战之一。一个更可持续的能源经济可能是可实现的光催化剂，可以生产氢燃料从水，使用阳光作为唯一的能量输入。氢被认为是一种“绿色”燃料，因为它通过重整水释放其储存的能量。已知的光催化剂的问题在于它们的能量转换效率低，也就是说，它们从太阳光吸收大量能量，但是这些能量中只有一部分被转换成可用的燃料。 本计画研究利用“铁电”光吸收体来增加能量转换效率。采用微观、光学、电学和化学等方法对新型铁电吸光材料进行了研究。这项研究是由博士后助理和研究生进行的。所有小组成员都接受了材料准备和应用现代仪器和技术进行表征的培训。还为来自代表性不足群体的本科生创造了新的实习职位。当地学校和校园里的化学展激励孩子们学习自然科学，解决清洁能源等重要的社会问题。实验演示作为在线材料分发，以教育公众可持续燃料研究。在化学部化学催化计划的资助下，加州大学戴维斯分校的Osterloh博士正在研究一组由钙钛矿M：ATiO 3衍生的光催化剂材料中的铁电效应。这里，A是碱土元素，M是过渡金属离子。这些材料与第三代光伏器件和光催化剂的开发有关，可用于生产可持续能源。采用固相法和水热法从丰富的元素中合成了这些化合物，并用电子显微镜、X射线衍射、X射线光电子能谱和紫外维斯光谱对它们进行了表征。采用水氧化还原共催化剂对铁电体进行择位改性，制备了用于水裂解反应的铁电体光催化剂。介电极化实验，表面光电压谱，光催化和电化学测量的组合被用来确定铁电偶极子可以在多大程度上提高这些材料的光化学能量到燃料的转换。此外，该项目还培训研究生、研究生和本科生无机材料的制备以及表征其形态、结构和光化学的先进方法。开展外联活动，以吸引和激励下一代STEM学生进行催化研究。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。