In the context of reduction of the fossil energy resources and global warming, much research has been focused on renewable energy sources. The work of scientific initiation presented here is focused on this category since it contributes to the development of a device that stores solar energy in a chemical fuel: the hydrogen. This device is based on photo-electrolysis of water by a photoelectrochemical cell that produces hydrogen and oxygen under illumination of sunlight. The photoelectrode of this cell will be based on a glass substrate covered with a layer of transparent conductor (SnO2 doped with fluorine) more a layer of semiconductor thin-film (TiO2 doped with nitrogen). Nowadays, plasma technology arises as an alternative for processing of thin films because it allows larger process control, since it involves many parameters that can be changed to obtain films with different properties, and ensure good reproducibility, unlike what happens in conventional chemical processes. This work aims to study and use TiO2 thin films doped with nitrogen (TiOxNy) as photoelectrode of a photoelectrochemical cell. These will be grown using the reactive magnetron sputtering technique and subsequently characterized by their structure, morphology and chemistry through the use of the x-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy techniques. Moreover, the optical analysis will be performed through the spectrophotometry technique to measure the transmittance and reflectance of the films in order to determine the optical gap of the material. Finally, prototypes will be assembled in photoelectrochemical cells with water electrolyte and characterized in order to determine their efficiency for generate hydrogen.
News published in Agência FAPESP Newsletter about the scholarship: