The 2022 solar fuels roadmap

Renewable fuel generation is essential for a low carbon footprint economy. Thus, over the last five decades, a significant effort has been dedicated towards increasing the performance of solar fuels generating devices. Specifically, the solar to hydrogen efficiency of photoelectrochemical cells has progressed steadily towards its fundamental limit, and the faradaic efficiency towards valuable products in CO2 reduction systems has increased dramatically. However, there are still numerous scientific and engineering challenges that must be overcame in order to turn solar fuels into a viable technology. At the electrode and device level, the conversion efficiency, stability and products selectivity must be increased significantly. Meanwhile, these performance metrics must be maintained when scaling up devices and systems while maintaining an acceptable cost and carbon footprint. This roadmap surveys different aspects of this endeavor: system benchmarking, device scaling, various approaches for photoelectrodes design, materials discovery, and catalysis. Each of the sections in the roadmap focuses on a single topic, discussing the state of the art, the key challenges and advancements required to meet them. The roadmap can be used as a guide for researchers and funding agencies highlighting the most pressing needs of the field.

Automated summary

The performance of solar fuel generation devices has made progress, but still faces many scientific and engineering challenges. There is a need to significantly improve conversion efficiency, stability, and product selectivity at the electrode and device level. Additionally, maintaining these performance metrics while scaling up devices and systems and controlling costs and carbon footprint is crucial. This roadmap surveys various aspects of solar fuel generation, highlighting the current state of the art, key challenges, and advancements required to meet them. It can serve as a guide for researchers and funding agencies in addressing the most pressing needs of the field.