Scientists in Japan have made a breakthrough in splitting water and sunlight into hydrogen to be used as fuel. The new technology could be the beginning of an era of cheaper, more sustainable, and more abundant hydrogen fuel for application across a range of industries. A team from Shinshu University in the Nagano Prefecture of Japan published their new research in the media and their findings are making waves in the science world.
The principle is simple: using sunlight and water to generate hydrogen fuel
Most of the hydrogen being currently produced relies on natural gas as the feedstock, meaning it’s still a fossil fuel product and can’t be considered a truly “green” option. The new method being developed in Japan promises 100% sustainability and improved efficiency, and if the technology proves viable, it will uplift hydrogen’s potential as a clean energy source.
Prof Kazunari Domen of Shinshu University, senior author of the article on the technology, explained:
“Sunlight-driven water splitting using photocatalysts is an ideal technology for solar-to-chemical energy conversion and storage, and recent developments in photocatalytic materials and systems raise hopes for its realization. However, many challenges remain.”
The concept sounds simple but the photocatalysts are complex
The basic concept of splitting water into oxygen and hydrogen sounds simple, but the process is energy-intensive and requires a specialized kind of catalyst called a photocatalyst. The catalyst works by facilitating chemical reactions when exposed to light that break water down into its parts.
Dr. Takashi Hisatomi of Shinshu University, another study author, detailed some of the intricacies of the technology that make it stand out:
“Solar energy conversion technology cannot operate at night or in bad weather. But by storing the energy of sunlight as the chemical energy of fuel materials, it is possible to use anytime and anywhere.”
Domen and Hisatomi’s team delivered a successful proof of concept by employing a 1,076 ft² (100 m²) reactor for three years. This reactor delivered even better performance in actual sunlight than under laboratory conditions. Hisatomi is proud of the initial results achieved:
“In our system, using an ultraviolet-responsive photocatalyst, the solar energy conversion efficiency was about one and a half times higher under natural sunlight.”
Is the technology capable of real-life applications beyond the laboratory?
Hisatomi offered a candid take on the current capacity versus what’s needed to make the tech viable for scaling up:
“Simulated standard sunlight uses a spectrum from a slightly high latitude region. Solar energy conversion efficiency could be higher in areas where natural sunlight has more short-wavelength components than simulated reference sunlight. However, currently, the efficiency under simulated standard sunlight is 1% at best, and it will not reach 5% efficiency under natural sunlight.”
More research on photocatalysts is needed to propel the new technology
For the technology to progress and move beyond the 5% production-to-energy-use barrier, the research team says that more efficient photocatalysts need to be developed, meaning more researchers need to be working on them. He also says that larger experimental reactors need to be constructed. Domen explained:
“The most important aspect to develop is the efficiency of solar-to-chemical energy conversion by photocatalysts. If it is improved to a practical level, many researchers will work seriously on developing mass production technology, gas separation processes, and large-scale plant construction. This will also change how many people, including policymakers, think about solar energy conversion and accelerate the development of infrastructure, laws, and regulations related to solar fuels.”
In other news about hydrogen production, North America has cemented itself firmly in the green hydrogen game with the first operational plant in the United States, which is expected to produce three tons of hydrogen each day.