Photocatalytic splitting of water using sunlight to create abundant and inexpensive hydrogen fuel is an important technical challenge for scientists and engineers. This technology has impact for the production of "solar fuels" that uses the resource of solar energy to convert water or carbon dioxide into higher valued chemicals and fuels with a lower environmental impact. It is becoming increasingly recognized that high efficiency solar water splitting processes will require multi-component, multi-functional photo-catalytic systems. These photocatalysts contain a semiconductor light absorber, a material that stabilizes the light absorber under the reactions conditions (insulators are often used for this function) and attached metal electrocatalysts that perform chemical transformations. In this project, fundamental understanding will result on how different components of these multi-functional photo-catalysts impact the performance of these systems. Ultimately, the knowledge will be used to form the foundation for developing predictive structure-performance relationships that would guide the design of the multi-component photocatalysts for efficient solar water splitting. The project also emphasizes a wide array of educational activities that build upon the Principal Investigator's (PI) research to promote engagement of students in science, technology, engineering and mathematics (STEM) disciplines. The project will result in new curriculum content for a massive open online course (MOOC) emphasizing sustainable energy topics. These activities include outreach to high school and undergraduate students from underrepresented groups, as well as strategies aimed at improving the utilization of the World Wide Web in reaching students and the general public.
This project will focus on fundamental understanding about the influence of insulating protective layers on the overall performance of metal-insulator-semiconductor (MIS) photocatalyst system for solar water splitting. The aim of the project is to identify the fundamental characteristics of the protective layers that impact the performance and tune these characteristics to design MIS photocatalyst with minimal junction losses. The project has two central objectives: 1) Developing a physically transparent model that will capture the essential features of the MIS photocatalyst systems, 2) Guided by the model, design MIS photocatalysts with optimal geometric characteristics. The PI will focus on some of the most promising semiconductors (Si, GaAs, and Cu2O) and their coupling to oxygen evolution reaction (OER) electrocatalysts (Ni, Ru, and Ir) through the insulating layers (HfO2 and Al2O3). The project will use characterization techniques that include atomistic characterization of the geometric structure of the MIS photocatalysts, analysis of electronic and optical properties of the multicomponent systems as well as rigorous measurements to assess the device-level performance.
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.
