Photocatalytic Degradation Of Phenol In Wastewater By Using CQDs/g-C₃N₄ Composite Catalyst

Metal-free photocatalysts represent a promising alternative to conventional metal-based semiconductors and are also environment-friendly.In this report,we prepared different compositions of a carbon quantum dots?CQDs?loaded on graphitic carbon nitride?g-C₃N₄?composite photocatalyst via a thermal method.The as-prepared CQDs/g-C₃N₄ composite photocatalysts were characterized by different instrumental techniques such as UV-visible,TEM,XRD,Raman spectroscopy,Transient photocurrent responses,XPS and Photoluminescence?PL?.The prepared samples were applied for the removal of phenol in wastewater under visible light irradiation.Under visible light irradiation,a CQDs/g-C₃N₄ composite prepared with 1:20 mass ratio resulted in faster reaction rate for phenol photodegradation than pristine g-C₃N₄ and all other prepared samples of composites.Spectroscopic and photoelectrochemical characterizations revealed that the composite formation of CQDs into g-C₃N₄ helps not only enhanced the production of photogenerated electron-hole pairs by extending the visible light absorption region,but also enabled electron-hole separation by band alignment in the CQDs/g-C₃N₄ composite junction,thus yielded more holes,and radicals to promote phenol degradation.These results encourage the researchers to focus on the potential application of sustainable metal-free photocatalysts in water purification and environmental protection.