Sintered NiFe₂O₄ Nanoparticles for the Photocatalytic Degradation of Malachite Green

The environmental contamination by hazardous pollutants, particularly Malachite Green (MG) dye from industrial activities such as the textile industry, poses a significant concern. This research investigates the production and application of NiFe 2 O 4 nanoparticles for the photocatalytic degradation of MG dye. NiFe 2 O 4 nanoparticles were synthesized via a hydrothermal method and sintered at various temperatures (500 °C, 600 °C, 700 °C, and 800 °C). Their structural and photocatalytic properties were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet–visible (UV–vis) spectroscopy. The NiFe 2 O 4 sintered at 700 °C demonstrated optimal photocatalytic performance, achieving a degradation efficiency of 99% due to its superior crystallinity and phase purity. Additionally, the impact of NiFe 2 O 4 ’s piezocatalytic properties on the degradation efficiency was explored by incorporating ultrasonic agitation during the photocatalytic process, which significantly enhanced the degradation efficiency. This improvement is attributed to the piezocatalytic-induced generation of reactive radicals. This study highlights the potential of NiFe 2 O 4 as a dual-functional material for advanced photocatalytic applications, leveraging the combined effects of visible light irradiation and ultrasonic agitation to effectively degrade organic pollutants.