CAREER: Synthesis of Compositionally Complex Oxides for Energy Conversion and Storage

技术摘要：这项由固态和材料化学项目支持的研究将产生新的固态材料，这将推进太阳能转换和电能存储的基础化学。在太阳能转换方面，重点是合成具有特定形态的过渡金属钨酸盐的复杂（混合金属）组合物，这些组合物将最大限度地吸收光和收集载流子以光催化水氧化。将开发的金属钨酸盐的合成方法包括电化学沉积，胶体悬浮液的溶胶-凝胶处理，水热合成和水相前驱体的喷雾热解。水无机反应化学的电位- ph （Pourbaix）图指导合成前驱体和反应条件的选择，以产生所需的组合物。然后，有了新的化合物在手，进行光催化的倾向将通过标准的光电化学方法进行探测。在电能存储方面，这些合成方法将应用于制造具有高比能材料的高比功率纳米材料，用于锂离子存储。反应可以在连续的步骤中结合起来，得到用于稳定锂离子电极的混合金属尖晶石结构材料。有了这些化合物，电池性能将通过标准的电化学方法进行测试。然后，可以通过热解（在合成过程中）或光化学沉积（在合成后的修饰步骤中）添加涂层来增强光催化剂中的载流子分离和电池材料的稳定性。固态材料处于可再生能源科学的前沿。这项由固态和材料化学项目支持的拨款直接解决了太阳能转换的挑战，从阳光和电能存储中产生化学燃料，以便在一天中的任何时候都能获得能源。在可预见的未来，这些问题将继续主导国家科技讨论。由于这门科学应用于能源领域的重大问题，因此迫切需要包括年轻科学家，以确保未来有一个强大而多样化的人才库。因此，该项目与华盛顿大学医学院非常成功的青年科学家项目（YSP）合作，开展了强有力的教育推广活动。YSP让高中三年级学生，最好是来自化学科学领域历史上代表性不足的群体，在夏天进入实验室十周，开始与一组研究人员一起工作。为了确保长期影响，高中生、研究生导师、研究生导师和PI之间的关系将在开始实验室研究之前的春季学期开始，并将持续到大学录取过程中。这项拓展活动的第二个目标是利用互联网社交网络与学生的同龄人分享研究成果和实验室经验。

TECHNICAL SUMMARYThis research supported by the Solid State and Materials Chemistry program will generate new solid state materials that will advance the basic chemistry of solar energy conversion and electrical energy storage. In solar energy conversion, the focus is on synthesizing complex (mixed-metal) compositions of transition-metal tungstates in specific morphologies that will maximize light absorption and charge-carrier collection to photocatalyze water oxidation. The synthesis methods for metal tungstates that will be developed include electrochemical deposition, sol-gel processing from colloidal suspensions, hydrothermal synthesis, and spray pyrolysis from aqueous precursors. Potential-pH (Pourbaix) diagrams from aqueous inorganic reaction chemistry guide the choice of synthesis precursors and reaction conditions to generate the desired compositions. Then, with new compounds in hand, the propensity to carry out photocatalysis will be probed by standard photoelectrochemical methods. In electrical energy storage, these synthesis methods will be applied for creating high specific power nanomaterials with high specific energy material for lithium-ion storage. Reactions can be combined in sequential steps to give mixed-metal spinel-structured materials for stable Li-ion electrodes. With these compounds, battery performance will be tested by standard electrochemical methods. Then, coatings that enhance carrier separation in photocatalysts and the stability of the battery materials can be added by pyrolysis (during synthesis) or by photochemical deposition (in a post-synthesis modification step).NON-TECHNICAL SUMMARYSolid-state materials are at the forefront of renewable energy science. This grant supported by the Solid State and Materials Chemistry program directly addresses challenges in solar energy conversion to generate chemical fuels from sunlight and electrical energy storage to have energy available at any time of day. These problems will continue dominate national science and technology discussions for the foreseeable future. Because this science is applied to big problems in energy, there is a pressing need to include young scientists to secure a strong and diverse talent pool for the future. Accordingly, this program has a strong educational outreach initiative in collaboration with the highly successful Young Scientist Program (YSP) at the Washington University School of Medicine. YSP brings high-school juniors, preferably from groups historically under-represented in the chemical sciences, into the laboratory for ten weeks during the summer and begin working with a team of researchers. Important for securing long-term impact, the relationship between the high school student, a graduate mentor, a graduate tutor, and the PI will commence during the spring term prior to starting laboratory research, and it will continue through the college admissions process. A second goal of this outreach is to share research findings and laboratory experiences with students' peers using internet social networking.