Light-energy conversion in photosynthesis

In natural photosynthesis, NADPH (reducing equivalent) and ATP (chemical energy) are produced via electron transfer chain reactions and photo-induced charge separation. Natural photosynthetic systems are able to efficiently adapt to fluctuating environmental conditions. Using natural photosynthesis as the ideal model system, we are performing in-vitro and in-vivo bio-electrochemical studies to better understand the dynamic self-organization and electrochemical properties of the photosynthetic reaction process.

Wave-length conversion materials

Energy-conversion systems, such as solar cells, photocatalysts, and natural photosynthetic systems in plants and algae, utilize sunlight as an energy source and function effectively within specific wavelength ranges. However, sunlight is comprised of a continuous wavelength range of varying light intensity, and the available solar light spectrum is altered by the surrounding environment. Therefore, the development of materials that are able to absorb or release light of a specific wavelength is highly desirable. We are focused on developing novel materials and energy-conversion systems that can function efficiently and stably in fluctuating natural environments.

Electron transfer catalysts (Electrocatalysts)

For the conversion of sunlight into useful chemical energy, photo-generated electrons and/or holes must be captured and utilized for chemical reactions that generate products beneficial to humans. To construct systems that efficiently convert light into chemical energy, catalysts designed to promote redox reactions are a critical requirement. From a practical viewpoint, such redox catalysts should not be constructed using precious metals and/or rare elements. With the aim of environmental sustainability, our group is researching ways to utilize abundant earth elements for developing redox catalysts with high redox activity and stability.

Li-metal batteries

For the practical application of solar cells, the development of next-generation and high-performance secondary batteries that are able to provide a constant, non-fluctuating supply of electricity is needed. We are currently engaged in developing Li-metal secondary batteries with particular focus on the analysis and control of Li-metal electrode interfaces.