Oxygen‐Doped Porous Ultrathin Graphitic Carbon Nitride Nanosheets for Photocatalytic Hydrogen Evolution and Rhodamine B Degradation

Abstract

Graphite phase carbon nitride (g‐C3N4) is a highly promising metal‐free photocatalyst. However, its applicability is restricted by low activity, due to weak quantum efficiency and small specific surface area. Exfoliating bulk crystals into porous thin‐layer nanosheets and introducing element doping have been shown to improve photocatalytic efficiency, but these methods are often complex, time‐consuming, and costly processes. In this study, we successfully synthesized porous oxygen‐doped g‐C3N4 (OCN) nanosheets utilizing a straightforward method. Our findings show that OCN have much higher light absorption and visible‐light photocatalytic activity than bulk g‐C3N4 (BCN) and nonporous g‐C3N4 (CN). The OCN photocatalyst has a remarkable hydrogen evolution reaction (HER) rate of 8.02 mmol·g‐1 h‐1, which is 8 times greater than BCN. Additionally, the OCN shows a high degradation rate of 97.3% for Rhodamine B (RhB). This enhanced photocatalytic activity is ascribed to the narrow band gap and superior electron transfer capacity. Our findings suggest a potential technique for generating efficient g‐C3N4 photocatalysts.