Selective oxidation of benzyl alcohol over TiO2 nanosheets with exposed {001} facets: Catalyst deactivation and regeneration

Increasing interest has been devoted to synthesizing TiO2 nanocrystals with reactive {001} facets (TiO2-001) as photocatalysts for potential applications, but relative research works on the photocatalytic stability of TiO2-001 nanocrystals are rarely reported. Here, we have prepared TiO2-001 using a facile hydrothermal method and studied its photocatalytic activity and stability toward selective oxidation of benzyl alcohol. The results show that TiO2-001 suffers from a serious deactivation. By a series of joint techniques, we find that lots of oxygen vacancies have been formed on the surface of the used TiO2-001, which is responsible for the loss in photoactivity of TiO2-001. A possible formation mechanism of the oxygen vacancies on the TiO2-001 surface is proposed. The regeneration of the catalyst can be realized by simply refluxing the used TiO2-001 in water at 100 degrees C. (C) 2012 Elsevier B.V. All rights reserved.