Design Principles for Structurally Diverse Bismuth-Containing Heteroanionic Materials

Non-technical Abstract: Bismuth-containing heteroanionic materials are an emerging class of compounds that combine multiple types of negatively charged atoms (anions) within a single, overall neutral structure, enabling new and useful properties beyond those found in traditional single-anion materials (e.g. oxides or halides). These materials are especially exciting for their potential applications in solar energy, light-driven chemical reactions (photocatalysis), and light emission (photoluminescence). The lone pairs of the bismuth ions as well as the layered structures of many bismuth-containing heteroanionic materials drive their unique electronic properties. However, only a small number of possible combinations have been studied. To address this shortage, researchers in the Skrabalak and Georgescu groups, with support from the Solid State and Materials Chemistry program in NSF’s Division of Materials Research, are collaborating to design, synthesize, and understand new bismuth-containing heteroanionic materials by combining computational and experimental methods. Their research explores how the types and arrangements of anions within these materials impact their properties. This project also supports broader educational and community goals, including training students in multidisciplinary science and sharing discoveries with the public through outreach programs like Science Fest at Indiana University. Technical Abstract: This project, supported by the Solid State and Materials Chemistry program in NSF’s Division of Materials Research, aims to uncover structure-property relationships in bismuth-containing heteroanionic materials. Density functional theory calculations are used to predict the most thermodynamically stable crystal and electronic structures across a targeted family of these compounds. Guided by these predictions, experimental efforts target the synthesis of selected phases and evaluate their optical and electronic properties, enabling direct correlation between structural motifs and performance. Also, aliovalent doping strategies are employed to create new materials that incorporate three distinct anion types – oxides, chalcogens, and halides – providing a platform to systematically vary anion identity and arrangement. Some new precursor chemistry toward nanocrystal synthesis of these same materials is evaluated for comparison purposes. Collectively, integrating computational methods with experimental synthesis and materials characterization generates new insights into how stoichiometry, anion coordination, and crystal- as well as nanoscale structure can be leveraged to tune the functional properties of this exciting class of materials. 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.