IEA-HIA Task 26 Research and Development Progress in Renewable Hydrogen Production Through Photoelectrochemical Water Splitting

Photoelectrochemical (PEC) hydrogen production, using sunlight to directly split water, is one of the key enabling technologies for a future where hydrogen is widely deployed as an energy carrier. However, the “traditional” semiconductor-based PEC material systems studied to date, including simple metal oxides such as TiO2, WO3 and Fe2O3, have not been successful in meeting all the performance, durability and cost requirements for practical hydrogen production. Technology-enabling advances in the development of new, advanced PEC materials and systems have been needed. Toward this end, the International Energy Agency's Hydrogen Implementation Agreement (IEA-HIA) Task-26, working in close conjunction with “Working Group on PEC Hydrogen Production” in the Fuel Cell Technology Program at the U.S. Department of Energy, has brought together experts in materials theory, synthesis, characterization and analysis from research sectors across the world. This endeavor has resulted in exciting recent progress over a broad range of PEC materials classes, including high efficiency crystalline semiconductors (e.g., III-V materials), promising thin-film semiconductors (including Fe2O3-,WO3-, and CuGaSe2- based films), novel photocatalyst powders (such as Cs-Modified WO3) and innovative photocatalyst nano-particles (e.g., MoS2). The research and development progress in these important PEC materials classes will be summarized, and key implications discussed.