Photo/Illutration Toyota Central R&D Labs Inc.’s artificial photosynthesis device is seen in Nagakute, Aichi Prefecture, on April 21. It has been increased in size to 36 centimeters per side, large enough for practical use, and its efficiency of conversion to organic matter has also been improved. (Jumpei Miura)

NAGAKUTE, Aichi Prefecture--Toyota Central R&D Labs Inc. said it has gone one better than even plants, improving the efficiency of its artificial photosynthesis technology to a world record level.

The Toyota Motor Corp. group research institute, based in Nagakute, Aichi Prefecture, announced on April 21 that the technology now surpasses plants in its conversion efficiency. Plants use sunlight to convert carbon dioxide (CO2) into organic matter in photosynthesis. 

The institute expects its artificial photosynthesis technology will lead to a promising means for an effective use of CO2.

Researchers are hoping it will become possible in the future to collect CO2 emitted from factories and use it in artificial photosynthesis by means of this technology.

The researchers conducted a study to use the energy of sunlight to generate formic acid, an organic substance, from CO2 and water. They assume the formic acid will be used as a raw material for generating hydrogen or as fuel for generating power.

Toyota Central R&D Labs succeeded in an artificial photosynthesis test in 2011. It has since been working to improve the conversion efficiency so more formic acid will be generated.

A restructuring of the device used in the latest study allowed the conversion efficiency to be improved from only 1.5 percent in 2017 to 7.2 percent, more than the corresponding figure for photosynthesis by plants.

That efficiency is the world’s highest to have ever been achieved in an artificial photosynthesis device of a comparable size, according to the institute.

“We hope to establish a technological foundation for practical use of the method by sometime around 2030,” said Takashi Shimazu, a Toyota Central R&D Labs director.