A group of Professor Tomoko Yoshida of Osaka City University has succeeded in improving the function of a photocatalyst that produces carbon monoxide from carbon dioxide using light energy.Carbon monoxide becomes a raw material for various organic substances by reacting with hydrogen.It is a technology that can be called artificial photosynthesis in the sense that it is the starting point for producing organic matter from carbon dioxide.
Organic substances containing carbon are not only an energy source for living organisms, but also fuels such as gasoline, and raw materials for various things such as plastics and chemical fibers that are indispensable for our affluent life.Until now, human civilization has relied heavily on fossil resources such as oil and coal.However, the increase in carbon dioxide in the atmosphere has become a problem due to the removal of them from the ground and their use, and there are also concerns about their sustainability due to the limited resources used.Currently, there is no stable way to reuse carbon dioxide released into the atmosphere other than photosynthesis by plants.It is hoped that this situation can be overturned if artificial photosynthesis can be established.
The method used this time is to convert carbon dioxide into carbon monoxide by absorbing the energy of sunlight with a semiconductor.A substance that promotes a chemical reaction by absorbing light in this way is called a photocatalyst.It has been found that the addition of fine silver particles to this photocatalyst significantly accelerates the reaction.In particular, it was clarified that carbon monoxide is efficiently generated when silver fine particles are made into a size of about 1 nm (1 nanometer is one billionth of a meter).
In the future, we aim to develop a catalyst to reduce carbon dioxide more efficiently and obtain carbon monoxide.Both the increase in carbon dioxide and the lack of energy are urgently resolved as problems on a human scale, but no definitive solution has been found.Artificial photosynthesis, which may solve both of these problems, will play an increasingly important role in the continuous development of human society.
Source:[Osaka City University] Elucidation of the function of silver nanoparticles that promote the photocatalytic reaction of artificial photosynthesis