Synergetic effects of the interfacial dyadic structure on the interfacial charge transfer between surface-complex and TiO2

Abstract

Surface-complex functional modification is a promising strategy in activating TiO2 for visible light harvesting. However, the fundamental nature of the interfacial microstructures between complex and TiO2, and how they affect the significant interfacial charge transfer process remain vague. In this work, a facile one-step visible-light-driven approach has been developed for the production of surface-complex and stable defects over TiO2 surface under normal ambient conditions. It is found that the photo-deposition of 2-naphthol on TiO2 can trigger a reconstruction of TiO2 surface to form a interfacial dyadic structure, which consists of conductive surface-complex and unique interfacial microstructures (Ti-O-C bonds and defects). defects. The interfacial defects (Ti3+ and oxygen vacancies) can be stabilized by the surface-complex coating, and introduce defective states in the band gap of TiO2. This unique interfacial dyadic structure can effectively promote the visible-light-driven photoelectric and photocatalytic performance. A corresponding mechanism is also proposed to elucidate the formation of this unique interfacial dyadic structure, and reveal its synergistic effect on the interfacial charge transfer behavior. This work contributes fundamentally to not only the mechanism studies, but also the rational design of novel and high-efficiency photocatalysts with high visible light harvesting.