Efficient promotion of charge transfer and separation in hydrogenated TiO/WO with rich surface-oxygen-vacancies for photodecomposition of gaseous toluene.

Oxygen-deficient TiO/WO constructed via the controllable temperature of hydrogen annealing is designed in view of combining the broad visible spectrum absorption with the prominent coupled semiconductor properties. Surface lattice disorder of TiO/WO arises at hydrogen annealing temperature of 200 and 300°C, while critical phase transition from TiO/WO to TiO/WO occurs at 400°C, both of which can introduce oxygen vacancies. The hydrogenated TiO/WO with rich surface-oxygen-vacancies exhibits much higher photocatalytic activity for decomposition of gaseous toluene than pristine TiO/WO under visible-light illumination (λ>420nm). The photoelectrochemical analysis shows that the improved electronic properties of oxygen-deficient TiO/WO enable dramatically efficient promotion of photoinduced charge transfer and separation, which is the key factor for the improved photocatalytic activity. It is hoped that the present work could boost ongoing interest for preparing various hydrogenated coupled semiconductors with enhanced activity for diverse photocatalytic applications.