Photosynthesis is the ultimate conversion of light to energy and one that scientists have been trying to replicate for years. Now, scientists have come up with a formula that may just be close enough, according to Science Mag.
Zetian Mi, an electrical engineer at the University of Michigan, Ann Arbor, and his team have developed a new copper- and iron-based catalyst that uses light to convert carbon dioxide (CO2) to methane. The innovation builds on years of work that found that copper particles proved promising in converting CO2 into other energy-rich compounds.
However, the efficiency was so low that researchers were pushed into considering pairing copper with other metals. In March of 2019, Mi and his colleagues found that a ruthenium- and zirconium-based catalyst grown on top of arrays of light-absorbing gallium nitride (GaN) nanowires efficiently converted CO2 to formate. But that was not a useful fuel.
Now, Mi and his team have come up with a new recipe for producing methane, a useful fuel. They used the same GaN nanowires then added tiny 5- to 10-nanometer-wide particles consisting of a mix of copper and iron.
Light into methane
Now, the setup works similar to photosynthesis. If light, CO2, and water are present, the system converts 51% of the energy in light into methane. And it does so pretty fast!
"This work presents a unique, highly efficient, and inexpensive route for solar fuels synthesis," write the researchers in their paper published in the Proceedings of the National Academy of Sciences. This is because all the materials in the current system are cheap and abundant.
Now, the system simply needs to improve its rate of efficiency. Once that is done, we may actually have a setup that truly mimics photosynthesis giving us a better option to polluting fossil fuels.