Organosilica-assisted superhydrophilic oxygen doped graphitic carbon nitride for improved photocatalytic H2 evolution

The regulation of surface wettability and heteroelement doping have been proved to be effective strategies to enhance photocatalytic H2 evolution activity of graphitic carbon nitride (CN) based photocatalysts. Herein, we report, for the first time, an organosilica assisted method was adopted to synthesize the superhydrophilic oxygen doped graphitic carbon nitride (O–CN). The presence of organosilica induced simultaneous oxygen-containing groups grafting and oxygen doping within carbon nitride substrate. The grafted oxygen-containing groups improved the surface hydrophilicity and water adsorption. Oxygen doping tailored electronic structure and localized electron distribution, contributing to extended visible light harvesting and elevated photoelectric conversion efficiency. As a result, the H2 generation rate of O–CN photocatalyst was 5.4 times higher than that of pristine CN photocatalyst attributed to the formation of hydrophilic groups and the oxygen doping.