Interfacial co-existence of oxygen and titanium vacancies in nanostructured TiO2 for enhancement of the carrier transport
The interfacial co-existence of oxygen and metal vacancies in metal oxide semiconductors and its highly efficient carrier transport are rarely reported. This work reports the co-existence oxygen and titanium vacancies at the interface between TiO2 and rGO via a simple two-step calcination treatment. Experimental measurements show that the oxygen and titanium vacancies are formed under 550 oC/Ar and 350 oC/air calcination conditions, respectively. This oxygen and titanium vacancies significantly enhances the transport of interfacial carriers, and thus greatly improves the performances regarding the photocurrent, the apparent quantum yield, and photocatalysis such as photocatalytic H2 production from water-splitting, photocatalytic CO2 reduction and photo-electrochemical anticorrosion of metal. A new “interfacial co-existence of oxygen and titanium vacancies” phenomenon, characteristics, and mechanism are proposed at an atomic-/nanoscale to clarify the generation of oxygen and titanium vacancies as well as the interfacial carriers transport.