Materials and systems for large-scale photocatalytic water splitting

Sunlight-driven photocatalytic water splitting has been studied as a means of producing renewable green solar hydrogen on a large scale at low cost. However, the research community has yet to define a common vision for practical solar hydrogen production, which requires not only photocatalyst materials that drive water-splitting reactions with high efficiency under sunlight but also systems and processes that can be scaled up. Herein, we discuss the current status and challenges in the development of materials, systems and processes for solar hydrogen production via photocatalytic water splitting. Despite the remarkable scientific progress in the development of photocatalyst materials and reaction systems over the past decade, many technological challenges remain before this technology can be put to practical use in terms of efficiency improvement, mass production, large-scale application of photocatalysts, cost reduction, process-efficiency improvement for reaction systems, and societal acceptance. It is, therefore, imperative to stimulate and accelerate research and development and large-scale demonstrations of hydrogen production via photocatalytic water splitting through collaborative efforts among industry, government and academia.