Rice University engineers have developed a photoreactor that turns sunlight into hydrogen at record-breaking speed. Unlike similar technologies, this device is both cost-effective and achieves a 20.8% solar-to-hydrogen conversion efficiency.
The new technology has the potential to serve as a starting off point for the development of many chemical reactions that use solar electricity to convert feedstocks into fuels.
“Using sunlight as an energy source to manufacture chemicals is one of the largest hurdles to a clean energy economy,” said Austin Fehr, a chemical and biomolecular engineering doctoral student and one of the study’s lead authors. “Our goal is to build economically feasible platforms that can generate solar-derived fuels. Here, we designed a system that absorbs light and completes electrochemical water-splitting chemistry on its surface.”
The device uses only sunlight and water to create green hydrogen all in one photoelectrochemical cell. The lab created the new technology by turning their pre-existing solar cell into a reactor that uses harvested solar energy to split water into hydrogen and oxygen.
Hydrogen is known as the most optimal fuel to serve as a back up for other renewable energy sources. It can be stored at high densities while maintaining a low carbon footprint and may produce electricity for sustained periods. So, when demand for energy is high but solar and wind energy are low due to weather or other factors, energy stored in hydrogen can step in.
Isolating hydrogen energy efficiently with this technology allows for sunlight to be the only energy input for hydrogen creation. The device can support a wide range of electron-to-fuel reactions that turn feedstocks, or plants and plant-based materials, into biofuels and biopower.
Engineers working on the project are confident in this technology’s ability to expand the abilities of solar power, hastening a transition away from fossil-fuel dependent energy.
“With further improvements to stability and scale, this technology could open up the hydrogen economy and change the way humans make things from fossil fuel to solar fuel,” said Fehr.