Activity Enhancement of Defective Carbon Nitride for Photocatalytic Ammonia Generation by Modification with Pyrite

12 July 2022, Version 2
This content is a preprint and has not undergone peer review at the time of posting.


Photocatalytic nitrogen fixation under ambient conditions is currently widely explored in an attempt to develop a sustainable alternative for the Haber-Bosch process. In this work we combine defect-rich C3N4, one of the most investigated photocatalysts reported in literature for ammonia generation, with earth-abundant and bioinspired FeS2 to improve the activity for ammonia production. By this combination, an activity enhancement of approx. 400 % compared to unmodified C3N4 was achieved. The optimal FeS2 loading was established to be 1 wt.%, with ammonia yields of up to 800 µg L-1 after irradiation for 7 hours. By detailed material characterization of the electronic and material properties of the composites before and after the photocatalytic reaction, we reveal that NH3 generation occurs not photocatalytically from N2, but via a light-induced reduction of =N-CN groups adjacent to nitrogen vacancies in the structure of defect-rich C3N4. FeS2 acts similar to a co-catalyst, enhancing the ammonia yield by π-back-donation from Fe-centers to the imine nitrogen of the defect-rich C3N4, thereby activating the structure and boosting the ammonia generation from cyano groups.


Nitrogen reduction
carbon nitride

Supplementary materials

Supporting Information to the Main Article
Includes addition data to support the finding of this study, including supporting diffractograms, spectra, and tables.


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.