Researchers from Panasonic Corp replicate the ability of plants to use sunlight, water and carbon dioxide to form organic compounds, with the same efficiency. Artificial photosynthesis will soon be a viable technology to produce a wide array of organic materials.
The solar efficiency of the system is 0.2 percent, the same efficiency of plants that are used as biomass. This value is calculated by dividing the energy of formed materials by the energy of applied sunlight.
The system uses nitride semiconductor electrodes and metal complexes electrodes. Water is oxidized using sunlight to produce hydrogen ions (H+) and electrons (e–) in the nitride electrodes. Carbon dioxide is reduced in the metal complexes electrodes; it reacts with two hydrogen ions and two electrons to form formic acid (HCOOH).
The system was initially faced with two challenges. First, multiple electrode materials were needed in the reduction of carbon dioxide. Second, it was difficult to fully utilize solar energy since increasing the intensity of sunlight does not increase the reaction current. Panasonic solved these problems by using the nitride semiconductor electrode.
This was not the first artificial photosynthesis developed by researchers. Toyota Central R&D Labs Inc reported a similar system in September 2011, but the efficiency of their system was only 0.04 percent.