A curly architectured graphitic carbon nitride (g-C3N4) towards efficient visible-light photocatalytic H2 evolution

Abstract

Graphitic carbon nitride (g-C₃N₄) is a promising metal-free photocatalyst for artificial photosynthesis and renewable solar-to-fuel conversion. However, the bulk g-C₃N₄ (GCN-B) powders derived from thermal polymerization only exhibit low photocatalytic efficiency. To this end, herein, we developed a precursor-reforming protocol to prepare the unique curly architectured g-C₃N₄ (GCN-CLA) by the direct calcination of the formed melamine-based precursor from a nitric acid-induced hydrothermal approach. Compared to the GCN-B, the GCN-CLA having thin-layer nanosheets with an average thickness of 10 nm possesses faster photogenerated electron–hole transport, larger specific surface area, fewer defect density, and stronger hydrogen proton thermodynamic driving force. Eventually, the GCN-CLA shows a superior photocatalytic H₂ improved rate of 1949 μmol g⁻¹ h⁻¹ under visible light, as well as a notable apparent quantum yield of 10.8% at 420 nm. Simultaneously, the photocatalytic activity of the as-fabricated GCN-CLA photocatalyst is not only much higher than that of the top-down acid treated g-C₃N₄ (GCN-AT) but also displays excellent photostability. Our work provides a new bottom-up precursor-reforming strategy for designing high performance g-C₃N₄ nanomaterials towards sustainable photocataysis applications.