Engineering single-atom rhodium-CN sites on covalent organic frameworks for boosting photocatalytic hydrogen evolution.

Developing efficient and stable photocatalysts for solar hydrogen (H) energy conversion is meaningful but challenging. Herein, a novel photocatalyst with Rh single atoms (Rh SAs) anchoring in β-ketoimine-linked covalent organic frameworks (TpPa-1) via RhCN sites is proposed for achieving highly efficient H production in phosphate buffer saline (PBS) solution with sodium ascorbate (SA) as sacrificial agent under visible light. TpPa-1 with abundant N and C-chelate sites provides a reliable basis for anchoring Rh single atoms.