Hana Kmentova3,Seyyedmohammadhossein Hejazi1,2,Mahdi Shahrezaei1,Alberto Naldoni1,Stepan Kment1,2
Czech Advanced Technology and Research Institute (CATRIN)1,Nanotechnology Centre, Centre of Energy and Environmental Technologies2,Palacky University Olomouc3
Hana Kmentova3,Seyyedmohammadhossein Hejazi1,2,Mahdi Shahrezaei1,Alberto Naldoni1,Stepan Kment1,2
Czech Advanced Technology and Research Institute (CATRIN)1,Nanotechnology Centre, Centre of Energy and Environmental Technologies2,Palacky University Olomouc3
The reduction of TiO<sub>2</sub> has been proven to enhance its photocatalytic activity by extending its light absorbance from UV to the visible part of the light spectrum and by optimizing the amount and position of defects that can act as co-catalytic sites. Traditional reduction method at elevated temperatures in contact with a reductant gas like hydrogen, has some disadvantages like phase transformation, sintering and even introducing impurities because of the harsh reaction conditions. In this contribution, we used the sono-reduction method in mild conditions at room temperature and aqua media under Ar atmosphere, to input defects at the surface of brookite as the most photoactive TiO<sub>2</sub> phase and to produce so-called “black TiO<sub>2</sub>”. We have shown that this strategy, without using a noble metal co-catalyst, could increase the H<sub>2</sub> evolution rate up to 3 times (from 19.3 to 58.5 µmol.g<sup>-1</sup>.h<sup>-1</sup>) in comparison with the pristine (white) sample.