Nanosized core-shell (NiFe₂O₄/TiO₂) heterostructure for enhanced photodegradation against polycyclic aromatic hydrocarbons

The global level of attention has been raised for photocatalytic pollutant removal technologies for degrading organic pollutants because of rising concerns about their toxicity. In this study, NiFe₂O₄/TiO₂ core shells and pure samples of NiFe₂O₄ and TiO₂ were synthesized using the sol-gel process and used to degrade naphthalene which is one among the polycyclic aromatic hydrocarbons (PAHs) pollutant. The synthesized materials were evaluated using a variety of analytical techniques, and the typical NiFe₂O₄/TiO₂ core-shell results showed good purity and a lack of other impurity structures. Through morphological characterization, the core-shell structure of NiFe₂O₄/TiO₂ has been established. However, the activity of visible light degradation was boosted by the generation of hydroxyl radicals after the electron-hole pair was delayed. Additionally, a lower band gap in NiFe₂O₄/TiO₂ than in pure materials promotes photocatalytic activity. Similarly, photocatalytic naphthalene elimination by the core-shell achieved 67% efficiency after 150 min of visible light exposure. Furthermore, the produced core-shell has a high magnetic property, making separation from the photo-irradiated solutions easier; as a result, recycling was likely successful up to three cycles. The photocatalytic mechanism of the NiFe₂O₄/TiO₂ composite was proposed. This research could also be applied to the degradation of other polycyclic aromatic hydrocarbon contaminants.