Photosynthesis Through Artificial Leaves, with Dr. Peidong Yang

Replicating Nature  As the effects of anthropogenic greenhouse gas emissions become increasingly well understood, researchers like Dr. Peidong Yang at UC Berkeley are developing technologies that address human-caused climate change with a nature-based approach. Dr. Yang’s artificial leaves capture sunlight and carbon dioxide and produce C2, a key precursory ingredient in the production of many everyday items.    Diving Deeper  Though synthetic fuels have been manufactured for over a century - by combining carbon monoxide and hydrogen - these new structures may be able to generate fuel in a more sustainable way by harnessing solar energy. The artificial leaves produce ethylene and ethane, showing that artificial leaves can create hydrocarbons; previously, similar structures have only been able to separate water into oxygen and hydrogen.  A few innovations make this process possible. One is the catalyst, a microscopic copper structure, flower-like in appearance. According to another scientist working on the project, Virgil Andrei, the copper nanoflowers can be adjusted, based on the desired outcome: “Depending on the nanostructure of the copper catalyst you can get wildly different products.” Another innovation occurs on the side of the device opposite the nanoflowers -    Benefits  The benefits for climate change are two fold. First, these artificial leaves can remove CO2 that’s already been released into the atmosphere by mimicking what natural leaves do through photosynthesis. These artificial leaves uptake CO2 from the air, and use it to make all sorts of different chemicals that can be utilized to create fuel.  The second major benefit is this technology is an opportunity to revolutionize the current chemical industry. Right now, the chemical industry is powered by fossil fuels converted into the liquid fuel that powers our society. Instead, this artificial photosynthesis allows scientists to create those same very useful chemicals from the CO2 being uptaken by the artificial leaves without any added emissions in the process. Though the carbon will be reemitted once this fuel is used, it works out to be a net carbon-neutral system because the cycle continues—the artificial leaves will reuptake this CO2 as well. So, this net carbon-neutral system is drastically better than the current fossil fuel based system driving our climate crisis.    Issues of Scale Though this artificial leaf technology is promising for a number of future applications, it’s not ready to be scaled yet. Though the trial system worked, it’s just one step towards developing a commercially viable product. Another scientist, Yanwei Lum, emphasizes that, “The performance is still not sufficient for practical applications.” Once the leaves’ durability and efficiency is improved, they will be adoptable for fuel production. Andrei is optimistic that this step forward could come in the next five to ten years.    Yang’s take on the future of Artificial Leaves  Currently, the costs and energy needed for the technology are relatively high just because of how new it is. But Yang is confident that they will be able to bring the costs done, as well as the energy needed for the actual chemistry to happen. He also notes that for this to actually revolutionize our fuel production, this technology needs to be implemented at a massive scale. He hopes to see policies mandating new carbon capture technology in the conversion industry down the road.    About our Guest Peidong Yang is a chemist, material scientist, and businessman. He is the S.K. and Angela Chan Distinguished Professor of Energy, as well as a Professor of Chemistry and a Professor of Materials Science at the University of California, Berkeley. Dr. Yang researches materials chemistry, solid state chemistry, inorganic chemistry, and physical chemistry, focusing on low-dimensional nanoscopic building blocks that are used to assemble complex architectures with novel chemical and physical properties.   Further Reading Andrei et al., Perovskite-driven solar C2 hydrocarbon synthesis from CO2 Ashleigh Papp (Berkeley Lab), Scientists develop artificial leaf that uses sunlight Department of Energy, Perovskite solar cells  Carly Kay (MIT), This artificial leaf makes hydrocarbons out of carbon dioxide   For a transcript of this episode, please visit climatebreak.org/photosynthesis-through-artificial-leaves-with-dr-peidong-yang