The direct generation of hydrogen from sunlight has long been considered the most elegant solution for H2 production, if then scalable. Until now, there has still been a deficit of suitable materials and large-scale system solutions. Researchers at the University of Cambridge in England have now found an approach that from salt or waste water, directly with the help of solar energy, can produce drinking water and hydrogen.
For this, chemist Chanon Pornrungroj has combined a solar vapor generator (SVG) with a photocatalyst (PC). Normally, pure water is required for photocatalysis. In order to be able to use dirty water as well, he designed a water evaporator powered by solar heat, which removes impurities. This condensed water can then (after mineral addition) be used for drinking and cooking, and also for subsequent H2 production.
The research group of Erwin Reisner deposited a photocatalyst for this on a nanostructured carbon mesh that absorbs both light and heat and generates water vapor. The photocatalyst then uses this water vapor to generate H2. Especially in regions without access to clean water could this be an important advancement.