Fe single-atom-modified g-C <sub>3</sub> N <sub>4</sub> via a facile oxygen-tolerant synthesis strategy for improved photocatalytic H <sub>2</sub> production
Wentao Xu, Yuting Tang, Tao Ding, Qichen Liu, Xusheng Zheng, Qing Yang
Abstract
Single-atom catalysts based on graphitic carbon nitride (g-C<sub>3</sub>N<sub>4</sub>) show high potential for hydrogen production photocatalytically. However, it is still a challenge to develop single-atom-based g-C<sub>3</sub>N<sub>4</sub> due to the complex synthesis procedures, limited active sites, and insufficient mechanistic understanding. Herein, a facile oxygen-tolerant synthesis strategy was developed that utilizes the nitrogen-rich structure of g-C<sub>3</sub>N<sub>4</sub> to capture Fe single atoms from ammonium iron citrate, successfully constructing an efficient photocatalytic composite. The resulting Fe single-atom-modified g-C<sub>3</sub>N<sub>4</sub> catalyst exhibited highly improved light absorption, charge carrier separation, and a substantially enhanced rate of H<sub>2</sub> production photocatalytically under visible light irradiation. Experimental results demonstrated that the optimal sample achieves a H<sub>2</sub> production rate of 683 μmol h<sup>-1</sup> g<sup>-1</sup>, representing a 425% enhancement compared to pristine g-C<sub>3</sub>N<sub>4</sub>. This study presents a facile oxygen-tolerant approach for metal immobilization using metal-organic precursors, where the nitrogen-rich framework of g-C<sub>3</sub>N<sub>4</sub> effectively captures Fe atoms as singular site within the composite. The developed synthesis strategy provides new insights for designing high-performance single-atom photocatalytic materials, potentially advancing the application and development of photocatalysis.