Hybrid photocathodes for solar fuel production: Coupling molecular fuelproduction catalysts with solid-state light harvesting and conversion technologies

Artificial photosynthesis is described as the great scientific andmoral challenge of our time.We imagine a futurewhere a significant portion of our energy is supplied by such technologies. However, many scientific, engineering and policy challenges must be addressed for this realization. Scientific challenges include the development of effective strategies to couple light absorption, electron transfer and catalysis for efficient conversion of light energy to chemical energy as well as the construction and study of structurally diverse assemblies to carry out these processes. In this article, we review recent efforts from our own research to develop a modular approach to interfacing molecular fuel-production catalysts to visible-light-absorbing semiconductors and discuss the role of the interfacing material as a protection layer for the catalysts as well as theunderpinning semiconductor. In concluding,we briefly discuss the potential benefits of a globally coordinated project on artificial photosynthesis that interfaces teams of scientists, engineers and policymakers. Further,we offer cautions that such a large interconnected organization should consider.