In a new study published in the Proceedings of the National Academy of Sciences, scientists from China and the United States found a more efficient way of generating renewable energy through artificial photosynthesis.
There is much interest in artificial photosynthesis because, compared to a solar cell, plants convert solar energy to another form of energy in a more efficient manner. A prior study published in the same journal in August of 2017 explored solar energy conversion in plants with the aim of improving the quality of solar cells.
The researchers imitated the process by which plants generate oxygen by creating an iridium catalyst with two metal centers.
Based on the tests conducted by the researchers, the catalyst has the necessary structure to support solar fuel photosynthesis. The lead author of the study, Dunwei Wang, an associate professor at Boston College, explains the significance of replicating photosynthesis artificially.
"Our research concerns the technology for direct solar energy storage. It addresses the critical challenge that solar energy is intermittent. It does so by directly harvesting solar energy and storing the energy in chemical bonds, similar to how photosynthesis is performed but with higher efficiencies and lower cost."
For the study, researchers focused on a catalyst with two atoms, and they chose iridium as the medium. Based on the tests they conducted on the catalyst, it can serve as an effective platform for artificial photosynthesis since it has high activity as far as water oxidation is concerned and is highly stable.
Catalysts or substances that increase the rate of chemical reaction can play a crucial role in generating renewable energy. Right now, the main focus of many researchers is to find a heterogeneous catalyst for artificial photosynthesis that can be used in large-scale industrial transformations.
The biggest problem scientists encountered in imitating photosynthesis to harness and store energy was the fact that the atomic structure of heterogeneous catalysts had a poor definition, making it complicated to assess mechanisms on a molecular level. Thanks to new technology, researchers were able to develop a better platform to study complex reactions in more than one active site.
The challenge in generating artificial photosynthesis is to search for the most durable heterogeneous catalyst for water oxidation. The process is crucial for photosynthesis, and mimicking the process will require the catalyst. In previous studies, researchers found the right homogeneous catalyst for the same function, but the issue lies in the catalyst's durability. As reported by Science Daily, Wang says that this study on artificial photosynthesis is promising for several reasons.
"For the first time, we have a glimpse of the potential of heterogeneous catalysts in clean energy production and storage."
Using the Advanced Light Source at the Lawrence Berkeley National Laboratory, Wang and his team determined the structure of the iridium catalyst. They conducted the study using the X-ray Absorption Near Edge Structure and the X-ray absorption fine structure.Wang continued that they were surprised by how simple and durable the catalyst is. At the same time, results from the test show it produces the desired water oxidation reaction.
The U.S. Department of Energy and the National Science Foundation, together with other Chinese agencies, funded the study, which could be the platform for discovering the best method to harness renewable energy using artificial photosynthesis.