Artificial photosynthesis system: solar energy conversion efficiency is higher than that of plants

Photosynthesis is a chemical process that changes light energy, carbon dioxide and water into glucose during plant growth This process not only stores solar energy, but also fixes the greenhouse gas carbon dioxide However, the photosynthetic efficiency of nature is generally not high, most plants are less than 1%, even the microalgae under the condition of bioreactor are less than 3% Scientists have been hoping to "artificial" photosynthesis, a clean, green process to reduce carbon dioxide and produce high-value chemicals The super molecular artificial photosynthesis system is that plants harvest energy from light Green leaves contain hundreds of pigment molecules, which can absorb light at a specific wavelength Artificial photosynthesis requires a molecular system that can absorb light, convert and separate electric charge, simultaneously drive the fuel manufacturing reaction, and effectively convert light energy into chemical energy Recently, researchers at the Brookhaven National Laboratory of the U.S Department of energy and the Virginia Institute of technology have designed a supramolecule that can do this based on a photocatalyst that can accelerate chemical reactions while absorbing light The photocatalyst consists of a ruthenium collection center connected to a single rhodium catalyst center This bridging molecule connects two metal transition electrons of ruthenium to rhodium catalyst, thus producing hydrogen The strategy of adding bacteria to water decomposition catalyst Harvard University developed an efficient artificial photosynthesis system based on Co-P water decomposition catalyst and Ralstonia eutropha: H 2 from water decomposition was used by bacteria, and isopropanol was produced from CO 2 In the production of bacterial biomass and liquid alcohol fuel, 180 g CO2 can be converted for every kilowatt hour of electric energy consumed, and the energy efficiency of CO2 reduction is about 50% The system can use the existing solar photovoltaic devices for power supply On the whole, the maximum energy efficiency of CO2 reduction using solar energy is about 10%, which is ten times of the plant photosynthetic system In other words, this system can be combined with the existing renewable energy power generation systems, such as solar energy, wind energy, tidal energy, etc., to convert the surplus electric energy into chemical energy storage, which is expected to solve the problem of unstable power supply of renewable energy generation In addition to the above-mentioned methods, the "semi artificial" photosynthesis system integrated with nano materials and living plants also works The research team of Massachusetts Institute of technology has used the method of lipid exchange membrane This kind of self-assembled CNTs can spontaneously penetrate into the lipid hydrophobic membrane around the chloroplast and become a part of plant cells, and can steadily enhance photosynthesis for a long time It is found that this method can enhance the electron flow related to plant photosynthesis - 49% in the extracted chloroplast and 30% in the living plant, which is mainly due to the fact that carbon nanotubes can increase the light capture ability of the plant, while ceria nanoparticles can greatly reduce the peroxide and other reactive oxygen species in the chloroplast In order to avoid the damage of chloroplast Reference link: http:// http://science.sciencemag.org/content/352/6290/1210 http://civil.utm.my/asmawisham/researchers-create-hydrogen-fuel-with-artistic-photosynthesis/