Japanese scientists have developed a new means of cracking water into hydrogen fuel using sunlight. Using a special photocatalyst, this new technology could help usher in cheaper, more abundant, and sustainable hydrogen fuel for various applications.

Currently, most free hydrogen is derived from natural gas feedstocks, meaning moving away from fossil fuels for this greener energy is not an option. However, this easily manufactured sunlight-powered method could prove pivotal if hydrogen is to become an alternative in the future.

“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,” Prof Kazunari Domen of Shinshu University explained.

The basic principle behind the new process is to split water into oxygen and hydrogen. While it sounds simple, this is energy-intensive and needs a catalyst, in this case, special ones called photocatalysts.

When exposed to light, these catalysts facilitate chemical reactions that break down water into constituent parts. The concept is not new, but most existing, so-called “one-step” ones are inefficient and have a meager solar-to-hydrogen energy conversion rate.

Another more sophisticated two-step excitation system also exists, and it is more efficient. In these systems, one photocatalyst generates hydrogen from water, while another produces oxygen.

Source: Science Direct

Image: Nature Nanotechnology