CAREER: Design Principles for Chalcogenide and Oxychalcogenide Aerogels: Synthetic Building Blocks, Mechanistic Understanding, and Emergent Properties

Non-technical Summary: The current technological revolution is fueled by the integration of science, engineering, and technology, with materials innovation at its core. Developing new materials, understanding their properties, and engineering them for specific applications are essential for addressing critical challenges in energy and environmental sustainability.

This CAREER award, which is jointly funded by the Solid State and Materials Chemistry Program in NSF’s Division of Materials Research and the Established Program to Stimulate Competitive Research (EPSCoR), focuses on developing advanced materials and uncovering their physicochemical properties. Eventually, these materials may support potential applications for separating toxic metals from water and improving energy storage in lithium-ion batteries.

At Jackson State University, the principal investigator and his team design and synthesize porous, nanoparticle-based metal (poly)sulfides and mixed anionic metal-sulfide-oxide materials. They investigate the fundamental science behind the design of this novel class of functional materials, namely chalcogenide and oxychalcogenide gels. Developing these materials with precisely tunable properties allows establishing design rules for electrochemical energy storage and selective binding with diverse metal ions, which could lead to materials capable of selectively binding and removing chemically distinct toxic metals from wastewater, contributing to cleaner water resources.

The materials are synthesized under scalable conditions at room temperature, using abundant, sustainable, and environmentally friendly elements, further enhancing their applicability. Beyond advancing the fundamental materials chemistry understanding for new sustainable energy and environmental technologies, this CAREER award project engages underrepresented minority students at Jackson State University and Mississippi K-12 in cutting-edge materials research, synthesis, characterization, and application.

By fostering diverse STEM talent, this project builds the workforce necessary to sustain the United States' leadership in science and technology.

Technical summary: Aerogels are a unique class of randomly ordered porous materials composed of interconnected colloidal-scale nanoparticles. Chalcogel, a chalcogenide-based aerogel, introduces a new chemistry of aerogels with incoherent structures of metal-chalcogenides, ideal for catalysis, energy storage and conversion, and separation. Despite its significant chemical and technological appeal, the compositional diversity, formation mechanisms, and local structures of chalcogels remain poorly understood.

Expanding research in this area could unlock significant strides in this emerging field. This CAREER award, which is jointly funded by the Solid State and Materials Chemistry Program in NSF’s Division of Materials Research and the Established Program to Stimulate Competitive Research (EPSCoR), advances the synthesis of self-assembling chalcogenide-containing gel by: (a) introducing novel chalcogenide-based building blocks, (b) combining known and new building blocks of chalcogenides with ion-exchangeable cations and (c) integrating the chalcogenide building blocks with oxoanions to create oxychalcogel, a new class of mixed-anionic gel.

Moreover, this CAREER award project also pursues a comprehensive mechanistic understanding of synthesis, local structure, and properties by: (a) investigating the sequential structural evolution of chalcogels through in-situ Raman spectroscopy, (b) employing state-of-the-art characterization techniques to delineate the local structures of amorphous chalco- and oxychalcogels, and (c) establishing synthesis-composition-structure relationships. Based on this new knowledge, this principal investigator and his research group develop materials with precisely tunable properties and establish design rules for electrochemical energy storage and selective binding with diverse metal ions.

Ultimately, this CAREER award project advances the fundamental science of chalcogenide-based gels while demonstrating their applications in lithium-ion batteries and wastewater treatment. Moreover, this CAREER award promotes the STEM workforce with underrepresented minorities at Jackson State University and Mississippi's K-12 students, thereby contributing to the development of the community, state, and country.

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.