As part of the energy transition, the production of hydrogen from solar energy appears to be an extremely promising means of storing and then producing energy. To develop on a large scale, water photoelectrolysis requires materials with high catalytic efficiency. Among the candidates considered, materials derived from barium titanates appear promising because their ferro- and piezoelectric properties could increase their photocatalytic effect. Therefore, we propose to synthesize BaTiO3 nanoparticles by flame spray pyrolysis and to make substitutions on Ba and O in order to study the effect of these modifications on the ferroelectric properties of the material. The addition of noble metal inclusions to the surface of the particles, likely to improve catalysis, will also be addressed. Finally, photocatalysis and piezocatalysis tests will make it possible to establish the links between ferroelectric and catalytic phenomena in this family of materials. This subject will be carried out in collaboration between the LEEL of the CEA and the SPMS of Centrale – Supelec.