An efficient and magnetically recoverable g-C₃N₄/ZnS/CoFe₂O₄ nanocomposite for sustainable photodegradation of organic dye under UV–visible light illumination

Effective improvement of an easily recoverable photocatalyst is equally vital to its photocatalytic performance from a practical application view. The magnetically recoverable process is one of the easiest ways, provided the photocatalyst is magnetically strong enough to respond to an external magnetic field. Herein, we prepared graphitic carbon nitride nanosheet (g-C₃N₄), and ZnS quantum dots (QDs) supported ferromagnetic CoFe₂O₄ nanoparticles (NPs) as the gC₃N₄/ZnS/CoFe₂O₄ nanohybrid photocatalyst by a wet-impregnation method. The loading of CoFe₂O₄ NPs in the g-C₃N₄/ZnS nanohybrid resulted in extended visible light absorption. The ferromagnetic g-C₃N₄/ZnS/CoFe₂O₄ nanohybrid exhibited better visible-light-active photocatalytic performance (97.11%) against methylene blue (MB) dye, and it was easily separable from the aqueous solution by an external bar magnet. The g-C₃N₄/ZnS/CoFe₂O₄ nanohybrid displayed excellent photostability and reusability after five consecutive cycles. The favourable band alignment and availability of a large number of active sites affected the better charge separation and enhanced photocatalytic response. The role of active species involved in the degradation of MB dye during photocatalyst by g-C₃N₄/ZnS/CoFe₂O₄ nanohybrid was also investigated. Overall, this study provides a facile method for design eco-friendly and promising g-C₃N₄/ZnS/CoFe₂O₄ nanohybrid photocatalyst as applicable in the eco-friendly dye degradation process.