Ultrathin Graphitic Carbon Nitride Nanosheets as Efficient Catalysts for Degradation of Pollutants under Visible Light

摘要

In this paper, ultrathin g-C3N4 nanosheets (U-CNs-4) were prepared via short time sonication-assisted exfoliation and solvothermal treatment method in ethylene glycol solvent. It was found that the obtained ultrathin g-C3N4 nanosheets with a thickness of ranges from 4 to 5 nm, exhibited a higher specific surface area of 35.7 m2 /g and larger electronic band structure (by 0.16 eV), enhanced photocurrent response and improved electron transport ability due to the quantum confinement effect. The photocatalytic activities have been proved by photocatalytic degradation Rhodamine B (RhB) and ciprofloxacin (CIP) under visible-light irradiation. Results show that the U-CNs-4 exhibited obviously enhanced photocatalytic activity in comparison with other samples. The degradation efficiency of RhB was 4.4 times higher than that of the bulk g- C3N4 (B-CN). The enhanced photocatalytic activity was due to the more active sites, the enhanced oxidation ability and improved electron transport ability, which improving separa- tion efficiency of photogenerated electron-hole pairs. Finally, the possible for the enhancing photocatalytic mechanism was revealed based on the active species trapping and electron spin resonance (ESR) experiments.