A research team led by Professor Kang Soon-hyung (Department of Chemistry Education) at CNU has developed a green hydrogen production technology that can produce hydrogen without the emission of carbon dioxide.

The research results were published online in the prestigious academic journal Nature Communications (impact factor: 16.6).

The joint research team at CNU, led by Professor Kang, addressed the low efficiency and stability issues compared to the commercialized electrolysis technology in the environmentally friendly photoelectrochemical hydrogen production method. They achieved high efficiency and stability by controlling the corrosiveness of the gallium arsenide (GaAs) photoelectrode through surface modification.

GaAs photoelectrodes, capable of absorbing almost all wavelengths of light in the solar spectrum, faced the challenge of rapid corrosion under the reaction conditions of the solution receiving sunlight.

To address this issue, the research team introduced a weakly crystalline TiO2 surface protection layer that does not affect the charge transfer between the photoelectrode and the electrolyte while protecting the photoelectrode and conducted stability tests for over 110 hours through coupling with a co-catalyst.

The GaAs photoelectrode-based self-powered photoelectrochemical water-splitting component developed by the research team achieved a solar-to-hydrogen conversion efficiency of 9.5%, approaching the target efficiency of 10% for practical application. The component also successfully demonstrated stable hydrogen and oxygen generation for over 10 hours.

This research is drawing attention not only to the photoelectrode but also to the practical development of surface layer control technology. The team is researching various surface control materials and technologies to achieve over 1,000 hours of photo-stability and is conducting research on the development of large-area photoelectrochemical systems based on GaAs photoelectrode materials.

Professor Kang led the research, with Dr. Kai Zhu's team from the U.S. National Renewable Energy Laboratory as a co-corresponding author and Dr. Maheswari Arunachalam, a postdoctoral researcher at CNU, as the first author. The research team is conducting continuous joint research with the U.S. National Renewable Energy Laboratory.