Researchers from the eponymous scientific network Fraunhofer have presented an autonomous compact module for extracting hydrogen from water using solar energy. The module supports simple scaling. From 100 m² The modules can produce 30 kg of hydrogen per year, which will allow an average passenger car to travel up to 20,000 km.

The development proposed by German experts uses the effect of photoelectrochemical catalysis. Although traditional solar panels are also placed inside this module, it is not an electrolyzer that splits water into oxygen and hydrogen using electric current. The energy generated by the solar panels is used for “turbocharging”, which accelerates the reaction of extracting hydrogen from water.

The main work of splitting water into oxygen and hydrogen is performed by a catalyst made of almost ordinary glass sheet. Specially selected materials, the film of which is not thicker than a few nanometers on each side, are applied to the glass by vacuum deposition. The deposition accuracy, as well as the semiconductor materials selected for it, play a role in increasing the catalyst efficiency.

When sunlight falls on glass, short-wave radiation is absorbed on the outer surface of the glass and produces oxygen. Long-wave radiation penetrates inside and produces hydrogen in the inner coating. Both gases are separated by a partition and collected separately. The dimensions of the working surface of the module are 50 cm.² An area consisting of modules with an area of ​​100 m² It will allow the production of up to 30 kg of ecologically clean hydrogen each year. For a hydrogen-powered vehicle, this will provide a range of 15,000 to 20,000 km.

Photoelectric catalysts are not a new invention. But they have always had one serious problem: very rapid wear. It is not clear how the German modules cope with this.