There are many ways in which fossil fuels could be replaced. Cars that rely completely on electricity are becoming more popular and scientists all over the world are working on developing sustainable fuels. One idea is to imitate plant photosynthesis: using the sun to harness energy and turn it into fuel.
Thomas Meyer, Professor at the University of North Carolina, is researching ways in which we could harness energy from the sun and then store it in chemicals, or fuels.
“The sun is a wonderful energy source but available only about six hours a day. The goal of our research was to extend the reach of the sun over a longer time to provide energy indefinitely”, says Meyer. “One way to do it would be to use the sun as an energy source for making fuels from water, hydrogen, or from CO2, storing and using the energy as fuel when the sun goes down.”
Zetian Mi, an electrical engineer at the University of Michigan, has now found a way to do just that. Mi and his research team have successfully calculated a reaction in which photosynthesis can be used to store energy in fuel.
“It is a solar analogue to plant photosynthesis. Instead of using water and CO2 to make O2 and biomass it would convert water into hydrogen or CO2 into a useful fuel”, says Meyer.
The impact of Mi’s discovery could be huge. “I began working in this area more than forty years ago. We carried out a light-driven chemical reaction and it was obvious from the results that it could be extended to energy conversion on a large scale. At the end of the story, we are helping to move the area forward because its impact would be enormous”, says Meyer.
So far, Mi only developed a computer model and calculation of the reaction. However, it appears to be the most efficient model in converting CO2 to methane for a fuel, Mi says.
Peidang Yang, Professor at the University of California, is working on similar research. “In general, this is all about ‘Photon-in, and chemical-bond out’, so the artificial photosynthesis and natural photosynthesis follow the same general energy transfer scheme, although the exact light absorbers and catalysts are quite different”, he says.
Yang and his team have found a metal that can be used to turn CO2 into carbon monoxide, which can then be used by the industry. “As part of the process in constructing system of components, this approach will help with artificial photosynthesis”, says Yang.
The next steps will be to improve the efficiency of the current system and make it more accessible. If that happens, the new approach to artificial photosynthesis could offer energy from sunlight even after the sun goes down.