Preparation of visible-light-response TiO2 photocatalyst by hydrothermal reduction

Aiming at obtaining a visible-light-response photocatalyst with high contaminants removal in high-salinity wastewater, the surface modification for commercial titania (P25) photocatalyst were studied by hydrothermal reduction, and Ti3+ doped photocatalysts with visible light response were prepared. The influence of changing conditions in hydrothermal reduction on the photodegradation for methyl-orange in high-salinity wastewater using these catalysts was explored under irradiation of visible light. The results show that the hydrothermal reduction can not only remove some oxidized functional groups on the P25 surface, but also forms a heterojunction structure by reducing TiO2 crystals to amorphous TiO2. The introduction of Ti3+ into the catalyst by reducing Ti4+ in TiO2 can expand the visible light response of the catalyst, thereby providing the catalytic activity excited by visible light. The activity of methyl orange of P25 modified by hydrothermal reduction using ethanol is the highest under the excitation of visible light, and the removal rate of 5 h for methyl-orange is up to 95%. In addition, the mild hydrothermal reduction process also ensures the catalyst stability, thus the removal rate of 5 h for methyl-orange exceeds 90% in the repeated photodegradation experiments. Copyright No content may be reproduced or abridged without authorization.