New Material Uses Light to Make Hydrogen From Water
Hydrogen is a useful fuel and a key ingredient in industry, but most of it is still made from natural gas, a process that releases carbon dioxide. Chemists at Oregon State University have found a new material that uses light to pull hydrogen out of water instead.
The team, led by Kyriakos Stylianou of the OSU College of Science, works with metal organic frameworks, or MOFs. These are crystals full of tiny pores, built from metal ions joined by organic linker molecules. Because their structure can be tuned, scientists can design them for different jobs. Nearly 100,000 MOFs have already been made in labs.
For this study, the researchers focused on one called BVR-19. It contains an unusual bond between two sulfur atoms. When light hits the material, that bond briefly breaks and creates very reactive sulfur, which helps move electrons to where they are needed to make hydrogen.
The big win is that BVR-19 does not need an extra, expensive metal catalyst to do its job. It also forms on its own in water at room temperature, so making it takes less energy. Stylianou says this is a different way of thinking about how such materials should be designed.
Cost is the hurdle for clean hydrogen today. According to the university, hydrogen from natural gas costs about $1.50 per kilogram, while green hydrogen costs roughly $5. By comparing versions of the material with different metals, the team worked out new design rules that could help bring that gap down over time.
The findings were published in the Journal of the American Chemical Society.
