Solar energy offers the potential for freeing people from use of fossil-based fuels. Today’s photovoltaic cells capture the sun’s energy and converts it to directly to electricity for immediate use or storage in a battery. All without greenhouse emissions. What if you were able to harness the sun’s energy in another way? Like using it to create hydrogen fuel instead of electrical current?
Researchers at UNC and NC State have come up with a technological breakthrough that could make this happen. Using dye-sensitized photoelectrosynthesis cells, this technology splits water into hydrogen and oxygen. The hydrogen turns into fuel that does into storage while the oxygen is harmlessly released into the air.
The system uses special molecules, known as chromophore-catalyst assemblies, that use the sun’s energy split the water. Those molecules attach to special nanoparticles that shuttle the hydrogenelectrons away to form hydrogen fuel.
The researchers had to overcome a couple of major challenges:
• The chromophore-catalyst assembly molecule kept breaking away from the nanoparticles, interrupting the conversion. Researchers found they had to add a protective coating to the assemblies to keep them in place.
• Once the bond between hydrogen and oxygen is broken, the system must move the hydrogen electrons away quickly so that they form hydrogen fuel. The solution was to coat each electron with an ultra-thin layer of titanium dioxide. This protects the electron and makes transportation faster.
The entire system requires very little external power to run. It releases no greenhouse gases. The best part is that this technology can work based on current technology. This could mean that sunlight-to-fuel conversion could become commercially viable in the next few years.