g-C3N4/MnFe2O4 p-n hollow stratified heterojunction to improve the photocatalytic CO2 reduction activity

• Published in: Chemical physics letters 2023-09, Vol.827, p.140698, Article 140698
• Main Authors: Liu, Zhiyu, Yang, Yanqiu, Guo, Zhiqiang, Kong, Lingru, Song, Peng
• Format: Article
• Language: English
• Subjects: g-C3N4 nanotubes; MnFe2O4; P-n heterojunction; Photocatalytic CO2 reduction
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2023.140698

[Display omitted] •g-C3N4 nanotubes have large specific surface area and more active sites.•p-n heterojunction interface generates electric field, accelerates electron and hole transfer, and inhibits carrier recombination.•The hollow hierarchical heterogeneous structure shortens the carrier migration path, which is conducive to charge separation and transfer. Graphite carbon nitride (g-C3N4) is considered as a promising photocatalyst for CO2 reduction. However, they have problems such as small surface area and fast electron hole recombination rate, so how to improve the photocatalytic efficiency of g-C3N4 remains a great challenge. In this paper, g-C3N4/MnFe2O4 p-n heterojunction composites were synthesized successfully, and their photocatalytic activity for CO2 reduction was tested. We constructed g-C3N4 nanotubes to increase its specific surface area and increase the active sites available for reaction. The structure of p-n heterojunction promotes electron hole separation. The results indicate that under visible light irradiation, CO yield of g-C3N4/MnFe2O4 composite can reach 1136.8 μmol h−1 g−1 when the molar ratio of g-C3N4 microtubules to MnFe2O4 is 10:3, which is 14 times of g-C3N4 microtubules and 29 times of g-C3N4. This study provides some guidance for the design of g-C3N4 based heterojunction.