Few-Layer C2N: A Promising Metal-free Photocatalyst for Water Splitting

Successful synthesis of the nitrogenated holey two-dimensional structures C2N (Nat. Commun. 2015, 6, 6486) using simply wet-chemical reaction offer a cost-effective way to generate other 2D materials with novel optical and electronic properties. On basis of the density functional theory calculations, we investigate electronic properties of monolayer and multilayer C2N. We find that few-layer C2N have a direct bandgap and the direct bandgap of the system can vary from 2.47 eV for monolayer to 1.84 eV for a five-layer. Besides, for the few-layer C2N, appropriate band gap, band edge alignments, and strong visible-light absorption demonstrate it may be a potential metal-free visible-light driven photocatalyst for water splitting.