Solar Fuel Production Based on the Artificial Photosynthesis System

Models of photosynthesis mimetic systems, the so-called artificial photosynthesis systems, have been investigated since the 1970s for the purpose of tapping solar energy. With the deterioration of the global environment in the 21st century, attributed to global warming and greenhouse gas emissions, it has become imperative to identify new fuel sources such as solar energy to replace fossil fuels. Among the new fuel production systems, those involving the use of solar energy have attracted attention; examples are systems that produce hydrogen through water photolysis and those that produce methanol by CO2 reduction with the aid of an artificial photosynthesis system. As hydrogen and methanol are low-carbon fuels (the emission of CO2 from the combustion of these fuels is low), they are considered to be alternatives to fossil resources. In this review, solar fuel production systems consisting of an artificial photosynthesis system, a catalyst, and an enzyme are discussed. These systems are expected to help in reducing CO2 and to promote the use of low-carbon fuels in the future.