Artificial Photosynthesis- Progress and Prospects
Authors: Atwater Harry A 
Published: February 2020

The Joint Center for Artificial Photosynthesis (JCAP) is the Fuels from Sunlight Energy Innovation Hub established by the US Department of Energy in 2010 to advance research and development on systems that convert sunlight, water, and carbon dioxide into a range of commercially useful fuels. JCAP has adopted an approach in which robust concepts for complete solar-fuels generators motivate basic scientific research targeting the accelerated discovery and integration of necessary components. Through a combination of scientific, engineering, and theoretical modeling approaches, JCAP has discovered novel materials and developed solar water-splitting prototypes that exhibit performance characteristics which were inconceivable just five years ago. As JCAP continues into a second five year term, they will capitalize on its scientific achievements and sophisticated technology development during the initial funding period by focusing on artificial photosynthetic systems that produce carbon-based fuels by reducing carbon dioxide. In this talk, both the accomplishments prospects of artificial photosynthesis will be discussed.

The initial five-year funding of JCAP resulted in various accomplishments that will be highlighted in this talk, including: discovery of new methods to protect light absorbing semiconductors from corrosion in aqueous solutions while still maintaining excellent electrical charge conduction to the surface; creation of an innovative high-throughput-experimentation facility with a coordinated pipeline for the rapid preparation, processing, screening, characterization, and data analysis of light absorbers and electrocatalysts; discovery of new mechanisms and materials for electrocatalytic water-splitting reactions, including earth-abundant catalysts with activity as good as those based on rare-earth metals; design, construction and testing of versatile, fully integrated test beds to facilitate the evaluation and optimization of new components and assemblies for solar-fuels generators; comprehensive multiphysics analyses and prototypes for the design of efficient and robust PEC H2 devices; life-cycle and techno-economic assessment of possible PEC systems; and standardization and development of benchmarking protocols for PEC component and device-performance validation.

As JCAP moves forward into its second five-year mission, JCAP will create the scientific foundation for a scalable technology that converts carbon dioxide into renewable transportation fuels, under mild conditions, with only sunlight providing the input energy. The approach of JCAP towards meeting this objective will be introduced in this talk including the three pillars of: (1) mechanisms: discovery and understanding of highly selective catalytic mechanisms for carbon dioxide reduction and oxygen evolution operative at mild conditions of temperature and pressure; (2) materials: accelerated discovery of electrocatalytic and photoelectrocatalytic materials and useful light absorber photoelectrodes for the selective, efficient CO2 reduction into hydrocarbon fuels; and (3) prototypes: demonstration, in JCAP testbed prototypes, of artificial photosynthetic carbon dioxide reduction components and oxygen evolution components that exceed natural photosynthesis in efficiency and rival it in selectivity.