Facile synthesis of Fe single-atom porous photocatalysts via direct metal atomization achieving efficient photocatalytic nitrogen fixation

Photocatalytic nitrogen fixation has been explored as a feasible pathway for ammonia synthesis. However, the convenient and efficient preparation of photocatalysts for nitrogen fixation remains a challenge. Meanwhile, the reaction pathway and mechanism of photocatalytic nitrogen fixation are unclear. Herein, single-atom Fe-porous g-C 3 N 4 (FPx) samples were manufactured using a one-step anneal technique via bubble template and direct metal atomization. Characterization results indicate that FPx has a porous structure and single-atom Fe. The porous structure exposed more active centers. Simultaneously, singleatom Fe changes the adsorption mode of N 2 from physical to chemical and turns the photocatalytic nitrogen fixation from the associative distal pathway to the associative alternating pathway. Consequently, without any sacrificial agent or cocatalysts, FPx presents a prominent increase in photocatalytic activity, reaching 62.42 & mu;mol h -1 g -1 , over fivefold larger than that of bulk g-C 3 N 4 . This work provides new insights into photocatalytic nitrogen fixation and achieves efficient N 2 photoreduction by constructing single-atom photocatalysts. & COPY; 2023 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

Photocatalytic nitrogen fixation is a promising approach for ammonia synthesis, but the preparation of efficient catalysts and the understanding of reaction pathway and mechanism remain challenging. In this study, single-atom Fe-porous g-C3N4 (FPx) samples were prepared via a one-step annealing technique, and FPx exhibited a porous structure and single-atom Fe, leading to enhanced photocatalytic activity due to the exposure of more active centers and the change of adsorption mode of N2. FPx achieved a remarkable photocatalytic activity of 62.42 μmol h-1 g-1 without any sacrificial agent or cocatalyst, which is over five times higher than that of bulk g-C3N4. This work provides new insights into photocatalytic nitrogen fixation and offers a strategy for efficient N2 photoreduction by constructing single-atom photocatalysts.