Na-mediated carbon nitride realizing CO 2 photoreduction with selectivity modulation.

The depressed directional separation of photogenerated carriers and weak CO ₂ adsorption/activation activity are the main factors hampering the development of artificial photosynthesis. Herein, Na ions are embedded in graphitic carbon nitride (g-C ₃ N ₄ ) to achieve directional migration of the photogenerated electrons to Na sites, while the electron-rich Na sites enhance CO ₂ adsorption and activation. Na/g-C ₃ N ₄ (NaCN) shows improved photocatalytic reduction activity of CO ₂ to CO and CH ₄ , and under simulated sunlight irradiation, the CO yield of NaCN synthesized by embedding Na at 550°C (NaCN-550) is 371.2 μmol g ^-1  h ^-1 , which is 58.9 times more than that of the monomer g-C ₃ N ₄ . By means of theoretical calculations and experiments including in situ fourier transform infrared spectroscopy, the mechanism is investigated. This strategy which improves carrier separation and reduces the energy barrier at the same time is important to the development of artificial photosynthesis.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)