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

Abstract

BackgroundPhotocatalytic 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. MethodsIn 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. FindingsThe 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.