Panasonic has recently developed an artificial photosynthesis system that, using a simple and straightforward process, can convert carbon dioxide into clean organic materials with what it says record efficiency. This development may lead to the creation of a compact way of capturing pollution from incinerators and electric power plants and converting them into harmless – even useful – compounds.
Over the last few years, we've covered a number of artificial photosynthesis systems that could use sunlight to split water into hydrogen and oxygen. Some of them could do it cheaply and reliably, operating ten times more efficiently than real leaves.
The "artificial photosynthesis" developed here, however, takes things to a new level: it not only splits water into its atomic components, but also uses the resulting hydrogen to convert carbon dioxide (CO2) into formic acid (HCO2H) – the same stuff that makes ant bites sting, and is used in the chemical industry to make dyes and fragrances.
The technology sees light shine on a nitride semiconductor inside a water container, where the nitride acts as a photo-electrode and splits water into oxygen and hydrogen. Then, boosted by a metal catalyst, the electrons are excited with enough energy for CO2 reduction to take place and create formic acid.
The solution is remarkably simple, much more so than previous attempts. Past systems relied on complicated multi-stage processes and often employed complex organic compounds. But, the researchers found, such compounds can limit overall performance. With their all-inorganic artificial photosynthesis system, the researchers achieved a record efficiency of 0.2 percent, which they claim is a significant improvement over previous results.
Crucially, because this system is scalable, can rely on both direct sunlight and focused light, and the amount of reaction products is exactly proportional to the light power, the researchers say it could be used to capture and convert wasted carbon dioxide from incinerators and electrical generation plants.
Source: Panasonic Corporation