Visible-light active metal nanoparticles@carbon nitride for enhanced removal of water organic pollutants

Graphitic carbon nitride (gCN) modified with metal nanoparticles (MNPs) has gained great interest as an effective photocatalyst for the photocatalytic removal of organic pollutants from water. Herein, a series of x% Au@gCN and x% Ag@gCN nanohybrids were fabricated via a feasible in-situ reduction/deposition method using non-toxic reducing agents. The prepared MNPs@gCN materials were characterized using several standard characterization and analytical techniques. Their photocatalytic activity toward the degradation of different organic pollutants was studied. The modification of the bulk gCN with MNPs using varying ratios of Au and Ag NPs in the final nanohybrids could improve the visible-light harvesting properties and suppress the photogenerated charges recombination. The 2% Au@gCN and 10% Ag@gCN photocatalysts exhibited a photocatalytic degradation of 98% and 97% of methylene blue (MB) within 20 min of visible light irradiation. The 2% Au@gCN achieved the highest photocatalytic activity with complete degradation of methyl orange (MO) under visible light irradiation for 100 min. Whereas the 10% Ag@gCN showed the highest photodegradation for ciprofloxacin (CIP) upon light exposure. The present work paves a practicable, low-cost, and scalable green approach to fabricate plasmonic gCN-based photocatalysts for superior removal of organic water pollutants under visible light irradiation. [Display omitted] •Feasible synthesis of metal NPs@gCN nanohybrids via reduction-deposition method.•Enhanced adsorption ability and visible-light harvesting of metal NPs@gCN.•Superior photocatalytic degradation of MB, MO and CIP by Au@gCN and Ag@gCN hybrids.•Excellent photostability and reusability of metal NPs@gCN for successive cycles.•Au and Ag NPs facilitate charge transfer and interfacial redox conversions of gCN.