Oxygen vacancies enable the visible light photoactivity of chromium-implanted TiO2 nanowires

Although computational studies have demonstrated that metal ion doping can effectively narrow the bandgap of TiO2, the visible-light photoactivity of metal-doped TiO2 photoanodes is still far from satisfactory. Herein, we report an effective strategy to activate the visible-light photoactivity of chromium-implanted TiO2 via the incorporation of oxygen vacancies. The chromium-doped TiO2 activated by oxygen vacancies (Cr-TiO2-vac) exhibited an incident photon-to-electron conversion efficiency (IPCE) of similar to 6.8% at 450 nm, which is one of the best values reported for metal-doped TiO2. Moreover, Cr-TiO2-vac showed no obvious photocurrent decay after 100 h under visible-light illumination. (C) 2020 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

Although metal ion doping can narrow the bandgap of TiO2, the visible-light photoactivity of metal-doped TiO2 photoanodes still needs improvement. A strategy using oxygen vacancies to activate chromium-implanted TiO2 has shown high incident photon-to-electron conversion efficiency and long-term stability under visible-light illumination.