Photocatalysis is emerging as a promising alternative to the anthraquinone method for hydrogen peroxide synthesis. H₂O₂ generation on conventional semiconductors occurs primarily by the two-electron ORR, the most thermodynamically favorable pathway. In this context, polymeric carbon nitride (CN) has gained significant attention as a promising photocatalyst for ORR, owing to its visible-light-responsive bandgap and suitable band edge positions. However, its performance is fundamentally limited by rapid charge recombination and inefficient in-plane charge transport. To overcome these limitations, single-atom catalysts (SACs) have been introduced as a compelling strategy, offering 100% atomic utilization, tunable metal coordination environments, and superior catalytic selectivity. Notably, rare-earth elements such as praseodymium (Pr) are particularly attractive for constructing SACs, due to their high oxygen affinity and demonstrated potential in heterogeneous catalysis, making them ideal candidates for enhancing the ORR performance of CN based materials.
This study fabricated tubular CN materials with atomically dispersed Pr single atoms via a facile hydrothermal method followed by impregnation. The optimized Pr-TCN catalyst exhibited excellent activity for photocatalytic H₂O₂ production from pure water under visible light, achieving a high yield of 227.37 μmol g⁻¹ h⁻¹ without requiring sacrificial agents. The charge transfer mechanism at the rare-earth and semiconductor interface was unraveled through In-situ infrared spectroscopy combined with first-principles calculations. This mechanistic understanding not only guides the design of efficient photocatalysts for sustainable H₂O₂ production but also underscores the industrial promise of single-atom catalysis.
This work entitled “Rare earth praseodymium single atoms on g-C₃N₄ tubes for enhanced in-plane charge transfer towards H₂O₂ production in pure water” was published on Acta Physico-Chimica Sinica (published on October 25, 2025).