Russian and Czech scientists have developed a new 2D material that can produce hydrogen from fresh, salt, and polluted water with the help of sunlight.
The new material was jointly developed by Russia’s Tomsk Polytechnic University (TPU) and Czech Republic’s University of Chemistry and Technology, Prague, and Jan Evangelista Purkyně University in Ústí nad Labem (UJEP).
According to the scientists, the developed material is a three-layer structure with a 1-micrometer thickness.
The lower layer is a thin film of gold, the second one is made of 10-nanometer platinum, and the third is a film of metal-organic frameworks of chromium compounds and organic molecules.
“During the experiments, we watered material and sealed the container to take periodic gas samples to determine the amount of hydrogen,” explains TPU scientist and one of the study’s co-authors, Olga Guselnikova.
“Infrared light caused the excitation of plasmon resonance on the sample surface. Hot electrons generated on the gold film were transferred to the platinum layer. These electrons initiated the reduction of protons at the interface with the organic layer.”
“If electrons reach the catalytic centers of metal-organic frameworks, the latter were also used to reduce protons and obtain hydrogen.”
Experiments have demonstrated that 100 square centimeters of the material can generate 0.5 liters of hydrogen in an hour: It is one of the highest rates recorded for 2D materials.
“In this case, the metal-organic frame also acted as a filter. It filtered impurities and passed already purified water without impurities to the metal layer,” notes Guselnikova.
“It is very important, because, although there is a lot of water on Earth, its main volume is either salt or polluted water. Thereby, we should be ready to work with this kind of water.”
Both the Russian and Czech teams are hoping to improve the material even further so that it becomes efficient for both the infrared and visible spectra.
“The material already demonstrates a certain absorption in the visible light spectrum, but its efficiency is slightly lower than in the infrared spectrum,” contends Guselnikova.
“After improvement, it will be possible to say that the material works with 93% of the spectral volume of sunlight.
Image and content: TUV AUSTRIA/TPU