A Photoelectrode for Solar Hydrogen Production
The Ulsan National Institute of Science and Technology (UNIST) announced on Nov. 9 that its research team has developed a high-performance and high-stability photoelectrode with a module system that effectively protects an organic semiconductor material from water.
A photoelectrode for solar hydrogen production is made of a semiconductor material that produces charged particles by absorbing solar energy. The particles react with water on the surface of the electrode, and then hydrogen and oxygen are produced. Since this reaction occurs in water, researches on stable metal oxide inorganic semiconductors have been conducted with regard to photoelectrodes. In the meantime, organic semiconductor materials, which are higher in hydrogen production efficiency, have not been used as photoelectrodes due to their vulnerability to water.
The research team, however, succeeded in producing the organic semiconductor electrode that is highly stable in water by using the module system composed of a liquid metal, a nickel foil and a catalyst grown directly on the foil.
The nickel foil prevents direct contact between water and the organic semiconductor and the catalyst assists in the reaction. In addition, the liquid metal between the foil and the semiconductor blocks water without blocking the flow of charged particles.
The research team explained that the hydrogen production efficiency of the photoelectrode is 4.33 percent, more than twice those of existing inorganic semiconductor photoelectrodes. Details of the research are available in the Nov. 2 edition of the Nature Communications journal.