UNS:Collaborative Research: Investigating Interfacial Sites in Metal/TiO2 Photocatalysts with in situ Spectroscopy and Computational Modeling

Worcester Polytechnic Institute, Worcester MA

Investigators

Abstract

1510810(Li) & 1511672 (Deskins) This collaborative research is focused on fundamental studies of photocatalysts based on metal/titania nanocomposites. Titania photocatalysts have been extensively studied in water/air purification and solar fuel generation. Depositing metal nanoparticles on titania surfaces can greatly improve the utilization of photonic energy in carrying out targeted surface reactions. However, little is known about the exact structure and function of catalytic sites in the interfacial region between the metal and titania phases. This research will potentially lead to better design of innovative semiconductor photocatalysts based on earth-abundant elements for efficient solar energy conversion. The project will also support educational activities to broadly and effectively disseminate sustainability concepts to the public, and provide opportunities for full participation of women and underrepresented minorities in STEM fields. The specific aim of this project is to investigate how interfacial, low coordination metal sites alter (i) product selectivity of copper/titania and (ii) reactivity of tin/titania nanocomposites in photocatalytic reduction of carbon dioxide into fuels. Metal/titania nanocomposites containing interfaces between individual components have demonstrated enhanced reactivity in solar photocatalysis. Knowledge regarding interfacial sites is important for photocatalysis research, but understanding is currently limited and without strong theoretical basis. In this project, rationally designed interfacial sites will be synthesized using inorganic and organometallic precursors, extensively characterized with a combination of techniques, and evaluated in photocatalytic carbon dioxide reduction. The structure and function of the synthesized interfacial sites will be investigated using in situ spectroscopic techniques (FTIR and EPR) and computational modeling (density functional theory). Through the proposed research, the PIs hope to establish structure-function relationships for interfacial sites that are also applicable to many other (photo)catalytic systems. The technology investigated potentially is very important to the understanding and commercial application of photocatalysis. Especially important is the link between theory and experiment which has the potential to advance technology beyond the specific example of carbon dioxide reduction explored in the proposed work. The PIs propose to integrate their research with education via undergraduate mentoring and curriculum development. Students working on the proposed research project will receive interdisciplinary training in a field of great importance toward a sustainable energy future and reduced greenhouse gas generation.