Herein, two-dimensional (2D) TiO₂ mesoporous nanosheets with three to four C₃N₄ layers grown in situ are employed to design a core–shell 2D/2D van der Waals heterojunction (TiO₂/C₃N₄). Edge-terminated zero-dimensional (0D) Ti₃C₂ MXene quantum dots (TCQD) are subsequently integrated in the C₃N₄ surface via electrostatic interactions. The constructed 2D/2D/0D TiO₂/C₃N₄/Ti₃C₂ composite heterojunction photocatalyst exhibits enhanced CO₂ reduction activity compared to TiO₂, C₃N₄, TiO₂/C₃N₄, C₃N₄/Ti₃C₂ for CO and CH₄ production. A step-scheme (S-scheme) charge transfer mechanism operates for the prepared samples during CO₂ reduction, as authenticated by in situ X-ray photoelectron spectroscopy and electron paramagnetic resonance analysis. This study provides a paradigm of a rational structural design for regulating the number and type of heterointerfaces and further insights into the mechanism of multijunction photocatalysts. Copyright © 2020 Elsevier B.V. All rights reserved.
CitationHe, F., Zhu, B., Cheng, B., Yu, J., Ho, W., & Macyk, W. (2020). 2D/2D/0D TiO₂/C₃N₄/Ti₃C₂ MXene composite S-scheme photocatalyst with enhanced CO₂ reduction activity. Applied Catalysis B: Environmental, 272. Retrieved from https://doi.org/10.1016/j.apcatb.2020.119006
- 2D van der Waals heterojunction
- Photocatalytic CO₂
- In situ X-ray photoelectron spectroscopy