Enhanced nitrogen photofixation performance of g-C₃N₄ nanosheets anchored with Bi₂O₂CO₃ and Bi₂O₃ under simulated solar light

Background: Photocatalytic nitrogen fixation process has been considered an eco-friendly technology. Among visible-light-triggered photocatalysts, g-C₃N₄ is an excellent choice, due to its some attractive features. Nonetheless, activity limiting factors for photocatalytic proficiency of g-C₃N₄ are small specific surface area, limited absorption of visible light, fast recombination of photogenerated charges, and poor carrier transportation. Methods: In this study, we anchored Bi₂O₂CO₃ and Bi₂O₃ nanoparticles over the nanosheets of g-C₃N₄ through a facile one-pot refluxing method. The resultant g-C₃N₄ nanosheet/Bi₂O₂CO₃/Bi₂O₃ photocatalysts displayed superior photocatalytic nitrogen fixation performance compared to the components. Findings: The amount of ammonia generation over the optimum nanocomposite was 4064 μmol L⁻¹ g⁻¹, which was 7.89 and 2.19 folds as large as the g-C₃N₄ and g-C₃N₄ nanosheet photocatalysts, respectively. The impact of reaction media, Ar atmosphere, solution pH, and electron and hole scavengers was examined on ammonia production to gain more insights into the nitrogen fixation process. Finally, a p-n-n heterojunction mechanism was suggested for the outstanding N₂ photofixation reaction over the g-C₃N₄ nanosheet/Bi₂O₂CO₃/Bi₂O₃ photocatalysts.