Facile synthesis of magnetically separable Fe3O4/GO/g-C3N4 composite for superior photocatalytic degradation of naphthalene

The intentional discharge of polycyclic aromatic hydrocarbons (PAHs) into the aquatic system from different industrial units has posed a serious threat to human health. To address the concerns associated with PAHs misuse, an efficient approach for developing affordable photocatalyst materials for PAHs degradation is much needed. In this study, we have explored co-precipitation and hydrothermal methods to synthesize Fe3O4/GO/g-C3N4 ternary composites and utilized them as photocatalyst materials for the degradation of naphthalene. Fe3O4/GO/g-C3N4 nanocomposite demonstrated superior degradation performance, with 87.56% naphthalene degradation achieved in 140 min under visible light irradiation, far outperforming Fe3O4/GO (77.42%) and Fe3O4(69.42%). The enhanced degradation of naphthalene by the Fe3O4/GO/g-C3N4 composite was credited to the effective charge carrier separation and increased visible-light absorption induced by GO and g-C3N4 . The impact of operating parameters on the catalytic efficiency of the Fe3O4/GO/g-C3N4 catalyst was also examined. The findings of this study revealed that lower naphthalene concentration (10 mg/L), higher catalyst dosage (40 mg), and moderate pH conditions (pH 5 to pH 9) were favorable for photocatalytic activity. The degradation of naphthalene followed pseudo-first-order kinetics with a rate constant value of 0.0137 min(-1). The generation of radicals (center dot OH and O-2(center dot-)) liable for the degradation of naphthalene was corroborated through electron para-magnetic resonance analysis and quenching experiments. Furthermore, the Fe3O4/GO/g-C3N4 photocatalyst exhibited promising reusability in five consecutive cyclic runs, validating its excellent stability.

Automated summary

The intentional discharge of PAHs into the aquatic system poses a serious threat to human health. This study focuses on developing affordable photocatalyst materials for PAHs degradation. Fe3O4/GO/g-C3N4 ternary composites were synthesized and used as photocatalysts for the degradation of naphthalene. The Fe3O4/GO/g-C3N4 nanocomposite showed superior degradation performance, with effective charge carrier separation and increased visible-light absorption. The study also investigated the impact of operating parameters on catalytic efficiency and demonstrated the reusability and stability of the photocatalyst.