New Folding 2D‐Layered Nitro‐Oxygenated Carbon Containing Ultra High‐Loading Copper Single Atoms

Abstract The discoveries of 2D nanomaterials have made huge impacts on the scientific community. Their unique properties unlock new technologies and bring significant advances to diverse applications. Herein, an unprecedented 2D‐stacked material consisting of copper (Cu) on nitro‐oxygenated carbon is disclosed. Unlike any known 2D stacked structures that are usually constructed by stacking of separate 2D layers, this material forms a continuously folded 2D‐stacked structure. Interestingly, advanced characterizations indicate that Cu atoms inside the structure are in an atomically‐dispersed form with extraordinarily high Cu loading up to 15.9 ± 1.2 wt.%, which is among the highest reported metal loading for single‐atom catalysts on 2D supports. Facile exfoliation results in thin 2D nanosheets that maximize the exposure of the unique active sites (two neighboring Cu single atoms), leading to impressive catalytic performance, as demonstrated in the electrochemical oxygen reduction reaction.