Korean researchers are making artificial photosynthesis technology a reality to achieve “carbon neutrality,” which means making the net emissions of carbon “zero.” Artificial photosynthesis technology mimics natural photosynthesis and converts carbon dioxide into high value-added compounds such as ethylene, methanol, and ethanol under sunlight like plants. However, due to economic and technical limitations, it has remained only in laboratory-level research, and has been carried out separately by solar cell research and carbon dioxide conversion research. Research to implement true meaning artificial photosynthesis has only been conducted in laboratory conditions with a small area, but there is still a long way to go to practical use.
The Korea Institute of Science and Technology (KIST) said that a research team led by Oh Hyung-seok and Dr. Lee Woong-hee of the Clean Energy Research Center developed a nano-meter-sized tungsten-catalytic electrode that can obtain carbon monoxide in an electrochemical carbon dioxide conversion system. The research team combined carbon dioxide conversion systems with commercial silicon solar cells to produce large-scale artificial photosynthesis systems that can be driven by real solar energy.
The team developed a new tungsten-silver catalyst that can be applied to weather carbon dioxide conversion carbon monoxide generation systems. The catalyst showed more than 60% improvement in carbon monoxide production efficiency compared to conventional catalysts, and was stable for 100 hours of testing. Furthermore, branch-type tungsten-developed from the catalytic material perspective showed high efficiency due to the three-dimensional structure of the catalyst and the branch-shaped crystal structure through electron microscopy and real-time analysis.
A step further from the development of the catalyst, the researchers combined the carbon dioxide conversion system with a 120cm2 silicon solar cell and developed an artificial photosynthesis system that can be used without difficulty when connected to commercial solar cells. The system showed a high solar-complex conversion efficiency of 12.1%, the highest level of silicon solar cell-based artificial photosynthesis systems developed so far, and succeeded in converting carbon dioxide to carbon monoxide only in real outdoor environments, not laboratories.
Based on this study, the research team expects that if highly efficient artificial photosynthesis technology is used, carbon dioxide from steel mills and petrochemical plants can be converted to carbon monoxide to reduce greenhouse gases, and basic compounds produced in petrochemical processes can be produced through carbon neutralization.
This study is published in a recent issue of Applied Catalysis B: Environmental (IF: 16.683, Top 0.943% in JCR), an international journal on energy environment.