Domen Laboratory, participating in the project of Japan Technological Research Association of Artificial Photosynthetic Chemical Process (ARPChem), focuses on research and development for particulate photocatalysts and reaction systems to meet our future energy needs
Domen Laboratory consists of Domen-Hisatomi Laboratory in Research Initiative for Supra-Materials at Shinshu University and Domen Laboratory in Office of University Professors at The University of Tokyo. We are involved with pioneering research and development of particulate photocatalysts and reaction systems in the project of ARPChem to realize efficient and scalable water splitting using solar energy toward commercially-viable renewable hydrogen production.
Efficient use of solar energy requires the development of photocatalysts with narrow band gaps. In Domen-Hisatomi Laboratory at Shinshu University, we study particulate semiconducting oxides, oxynitrides, nitrides, oxychalcogenides, and chalcogenides as photocatalysts, because most of these materials absorb visible light strongly and have band structures suitable for water splitting. In addition, to promote charge separation and surface redox reactions, it is essential to modify such candidate materials with nanoparticulate cocatalysts based on metals and metal oxides. We investigate the correlation among preparation methods, physical properties, and functionality to improve the water splitting activity and durability of cocatalyst/photocatalyst composites. We have reported some innovative photocatalysts driving overall water splitting (i.e., stoichiometric decomposition of water into hydrogen and oxygen) under irradiation of light with wavelengths up to approximately 600 nm. In addition, we have demonstrated overall water splitting with the internal quantum yield of almost unity using a particulate oxide photocatalyst under near-ultraviolet irradiation.
Reaction system development
Large-scale use of solar energy requires the development of scalable photocatalytic reaction systems. In Domen Laboratory at The University of Tokyo, we develop panel reactors containing particulate photocatalyst sheets for scale-up. Photocatalyst panel reactors can release product hydrogen and oxygen gas bubbles smoothly. In addition, a 1-m2-sized photocatalyst panel reactor splits water under natural sunlight irradiation without a significant loss of the intrinsic activity of the photocatalyst sheets. Following the success of these preliminary investigations, we are developing larger photocatalyst panel reactors.
The laboratory collaborates widely with colleagues in Japan and abroad to promote the research from the perspectives of physical chemistry, catalytic chemistry, and chemical engineering. We also work with industrial researchers to develop large scale reactors and systems for recovery of product hydrogen to demonstrate a prototype model of the entire renewable solar hydrogen production process.