Surface oxygen vacancies of TiO2nanorods by electron beam irradiation for efficient photoelectrochemical water splitting

Abstract

In this work, a high energy electron beam (EBI) with an energy of 0.1 MeV was applied to modify the surface structure of TiO2nanorod arrays (NRs). We have found that the photoelectrochemical (PEC) water splitting activity of the EBI-TiO2photoanode was enhanced greatly compared to that of pristine TiO2due to the enriched oxygen vacancies (VO) introduced at the surface of TiO2NRsviaEBI treatment. The concentration of surface VOis easily controlledviathe adjustment of irradiation doses, which is a key factor in influencing the PEC performance. After modification, the photocurrent density is markedly promoted without typical doping or catalyst modification, and is approximately double that of the pristine TiO2. Systematic studies have been conducted to reveal the mechanism for the charge separation and transport induced by the EBI process.