Researchers from Switzerland, the US and Israel discovered a new way to efficiently split the water molecule into hydrogen and oxygen using sunlight and small particles of rust. The study published in the latest issue of Nature Materials brings new hopes for cheap and efficient hydrogen production.
The small particles, referred to as “champion nanoparticles” of haematite (crystalline iron oxide, or rust), are a few billionths of a meter in size. They are grown on top of an electrode, and resemble the shape of a cauliflower. Once placed in water and exposed to sunlight in a photoelectrochemical cell, the particles trigger the formation of hydrogen gas bubbles.
The electrons inside the haematite structure interact with the edges of grains of the particles. The movement of these electrons is much more efficient when the particles are positioned correctly and have no grain boundaries.
Scott Warren and Michael Graetzel from the University of Lausanne, Switzerland, the founders of the champion nanoparticles, managed to increase the effectiveness of their new photoelectrochemical cell, by optimizing the process through which the water water is split, and the energy from the sun is captured and stored in the form of hydrogen.
The scientists claim that their method is cheap and efficient, considering the low cost and great abundance of the material involved. They also point out that the produced hydrogen can be easily stored and transported.