RUI: Heterostructured Bismuth-Based Metal Oxides Photocatalysts for the Degradation of Chlorinated Organic Contaminants

Many organic compounds that contain chlorine can remain in the environment for a long time, potentially harming human health and ecosystems. Chlorinated organic solvents, such as trichloroethylene (TCE) and perchloroethylene (PCE), are common groundwater pollutants in the U.S. and worldwide. Many people have been exposed to TCE and PCE through contaminated drinking water, raising health concerns. Decomposing these contaminants is challenging because of the strong carbon-chlorine bond. This project aims to develop new catalysts based on bismuth oxide to break down these pollutants. The research will design earth-abundant, eco-friendly nanocomposites made of two metal oxides arranged in particular ways to degrade organochlorine compounds using sunlight. Adding a small amount of environmentally friendly carbon material will enhance the catalyst's activity. This project will engage students in research activities to enrich their education by exploring new knowledge, developing key skills, and inspiring students to pursue careers in STEM. The goal of this project is to develop visible light-activated photocatalysts based on heterostructured bismuth-based metal oxide nanomaterials for the sustainable degradation of persistent chlorinated organic contaminants. The hypothesis is that designing Aurivillius/pyrochlore Z-scheme heterojunctions of bismuth-based metal oxides will enhance the redox potential of the photocatalyst band gap, enabling the degradation of chlorinated organic pollutants under visible light. To achieve this, the project will develop bismuth vanadate/Bi2M2O7 catalysts with engineered Z-scheme heterojunctions to boost visible-light-driven catalytic activity. Incorporating carbon dots (CDs) as sustainable, alternative cocatalysts to noble metals on the surface of bismuth-based metal oxides will improve light absorption and charge transfer. The properties of bismuth-based Z-scheme heterojunction nanocomposites will be investigated using techniques such as electron microscopy, X-ray diffraction, electrochemistry, and UV-vis spectroscopy, providing fundamental insights into designing more effective catalysts. The photocatalytic activity of these materials will be evaluated in degrading chlorinated pollutants like trichloroethylene and perchloroethylene, with performance compared to established materials such as TiO2. The project will explore the relationship between material structure, band gap alignment, and the mechanisms of visible-light-driven degradation, aiming to optimize reaction conditions for high efficiency and minimal toxic byproducts. Ultimately, this work advances the development of visible-light-responsive Z-scheme photocatalysts, providing the science and engineering fields with a scalable platform for creating sustainable technologies that utilize solar energy to remove persistent environmental pollutants. 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.