Ultra-thin TiO2 sheets with rich surface disorders for enhanced photocatalytic performance under simulated sunlight

Abstract Ultra-thin hydrogenated black TiO2 sheets with rich surface disorders were prepared by a facile hydrogenation of submicrometer sized TiO2 sheets. Due to the reduced band gap of 2.81 eV, the light harvesting ability of black TiO2 sheets is enhanced in the visible range. In addition, the rich surface disorder reduces the primary particle-size and increases the surface area from 20.9 to 46.2 m2g-1, which enhances the population of active catalytic sites and substantially improves the photocatalytic activities both under visible light and full spectrum solar light. The mechanism tests indicate the black TiO2 sheets triggered photodegradation is a hole mediated process. Moreover, the catalyst shows long-term stability, which permits its potential application in the real waste water treatment.