1. Allochroic platinum/carbon nitride with photoactivated ohmic contact for efficient visible-light photocatalytic hydrogen evolution.
- Author
-
Sun, Wenhao, Cheng, Hongrui, Zhang, Jing, Fang, Xiao, Chen, Wenkai, Zhu, Jiefang, and Zheng, Yuanhui
- Subjects
- *
OHMIC contacts , *NITRIDES , *HYDROGEN evolution reactions , *SCHOTTKY barrier , *PLATINUM , *PHOTOCATALYSTS , *CHARGE exchange - Abstract
[Display omitted] • A sufficient and tunable ohmic junction can be built in allochroic Pt/CN. • The ohmic contact is formed by the photoconversion of semiconducting CN to metalloid. • The reversible photoconversion of CN is accompanied with a color change. • The ohmic contact between Pt and CN significantly enhances the HER activity. • The deactivation and regeneration mechanisms of the allochroic Pt/CN are proposed. The direct hybridization of Pt and g-C 3 N 4 generally forms a Schottky barrier between the two components, which unavoidably hinders the migration of photogenerated electrons from g-C 3 N 4 to the Pt cocatalyst. Herein, we report the first efficient allochroic Pt/g-C 3 N 4 photocatalyst that can form an ohmic contact through photoconversion of semiconducting g-C 3 N 4 to metalloid, accompanied with the charge carrier storage and photocatalyst color change, which is proved experimentally and theoretically. Through intermittent exposure of Pt/g-C 3 N 4 photocatalyst to air for a few minutes during photocatalysis, the photocatalyst shows the highest hydrogen evolution performances. The ohmic contacts greatly promote the electron transfer from the semiconducting g-C 3 N 4 to the Pt cocatalyst driven by the built-in electric field. In addition, the mechanism for the photocatalyst deactivation and activation is presented. The compositional tuning of the allochroic g-C 3 N 4 through light irradiation and exposure to air can control over the photocatalytic activity and long-term stability for hydrogen evolution. This report for the first time unveils the deactivation and regeneration mechanisms of SCN. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF