Synthesis of New Intergrowth and Nanostructured Metal Oxyhalide Photocatalysts

非技术概述迫切需要吸收可见光的材料，以便这种能量可以用于驱动其表面的反应，例如有望提供氢作为清洁燃料的太阳能水分解。金属卤氧化物是一类令人兴奋的光催化材料，但它们在使用时通常会转化为相应的金属氧化物，使其长期无效。最近，含铋金属卤氧化物的子集被鉴定为在它们用作光催化剂期间既吸收可见光又耐用。通过这个项目，在材料研究部的固态和材料化学计划的支持下，印第安纳州大学的Sara Skrabalak教授和她的研究小组将开发新材料，该材料将联合收割机不同的含铋金属卤氧化物用于太阳能水分解。这些新材料的原子级结构也被详细描述，以了解它们的结构如何提供可见光吸收和临界耐用性。这些材料也被合成为具有限定形状的晶体，以便表达最佳晶面以促进水裂解反应。这项工作提供了对材料特性的基本见解，有可能解决与利用太阳能相关的材料耐久性挑战。该研究与广泛的教育和推广活动相结合，促进对材料科学和太阳能的理解，以广大public.Technical summaryThis项目，由材料研究部的固态和材料化学计划的支持，将开发新的金属卤氧化物共生体的形式Bi 4 MO 8X-Bi 2LnO 4X的生长的合成方法。 这项工作的基本假设涉及的想法，共生体的形成和调制的化学计量，使他们的电子结构和内部电场的工程朝着增强的光催化效率和光稳定性相比，母体化合物。这项合成工作再加上详细的结构表征，高分辨率电子显微镜和X-射线全散射实验，使强大的结构-性能的相关性建立。最后一个目标是合成形状可控的Bi 4 MO 8X纳米晶，并研究其对光催化性能的影响。总的来说，本研究通过阐明局部和纳米级结构对这些有前途的杂阴离子材料的光电性能和光催化性能的作用，推进了耐用的金属卤氧化物的合成和设计。该项目还将通过与Wonderlab（位于印第安纳州布卢明顿的儿童科学博物馆）和印第安纳州大学的科学节合作，支持向非科学家介绍能源概念的教育和推广活动。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Nontechnical summaryThere is a critical need for materials that absorb visible light so that such energy can be used to drive reactions at their surfaces, such a solar water splitting which promises to provide hydrogen as a clean fuel. Metal oxyhalides are an exciting class of such photocatalytic materials but often they will be converted to their corresponding metal oxide upon use, making them ineffective long-term. Recently, a subset of bismuth-containing metal oxyhalides was identified to be both visible light absorbing as well as durable during their use as photocatalysts. With this project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, Professor Sara Skrabalak and her research group at Indiana University will develop new materials that combine different bismuth-containing metal oxyhalides for uses in solar water splitting. The atomic level structure of these new materials are also characterized in detail to understand how their structure provides both visible light absorption and critical durability. These materials are also being synthesized as crystals with defined shapes so that the best crystal faces are expressed to facilitate the water splitting reaction. This work provides fundamental insight into the properties of materials, with potential to address material durability challenges associated with harnessing solar energy. The research is paired with broad educational and outreach activities that foster understanding about material science and solar energy to the general public.Technical summaryThis project, supported by the Solid State and Materials Chemistry program in the Division of Materials Research, will develop synthetic methods for the growth of new metal oxyhalide intergrowths of the form Bi4MO8X-Bi2LnO4X. The fundamental hypothesis of this work involves the idea that intergrowth formation and modulation of their stoichiometry enables engineering of their electronic structure and internal electric fields toward enhanced photocatalytic efficiency and photostability compared to the parent compounds. This synthetic work is coupled with detailed structural characterization by high resolution electron microscopy and X-ray total scattering experiments so that robust structure-property correlations are established. A final aim focuses on the synthesis of shape-controlled Bi4MO8X nanocrystals and the study of their faceting on photocatalytic performance. Collectively, this research advances the synthesis and design of durable metal oxyhalides by elucidating the roles of local and nanoscale structure on the optoelectronic properties and photocatalytic performance of these promising heteroanionic materials. The project will also support educational and outreach activities that introduce energy concepts to non-scientists through partnerships with Wonderlab (a children’s science museum in Bloomington, Indiana) and Indiana University’s ScienceFest.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.