Synthesis of NiTiO3/TiO2 Composite Nanoparticles by a Green Approach: Application as Sonocatalyst for Dye Degradation

A novel NiTiO 3 /TiO 2 heterostructure was synthesized via a green sol–gel method using lemon juice as a natural precursor. The phase formation, structural, morphological, and optical properties of the synthesized composite were investigated using x-ray diffraction (XRD), Raman scattering, field-emission scanning electron microscopy (FESEM), and diffuse reflectance spectroscopy. XRD and Raman scattering results confirm the coexistence of both ilmenite NiTiO 3 and TiO 2 phases in the composite. The TiO 2 phase in the composite undergoes temperature-dependent phase transformation: it exists as anatase when calcined at 600°C, a mixture of anatase and rutile at 700°C, and pure rutile at 800°C. FESEM reveals that the synthesized NiTiO 3 particles exhibit spherical nanostructures. The NiTiO 3 /TiO 2 composites were investigated for their sonocatalytic activity in the degradation of rhodamine B under ultrasonic irradiation. The composite exhibited significantly enhanced sonocatalytic performance compared to pure NiTiO 3 , which can be attributed to the improved interfacial charge transfer and the synergistic effects between NiTiO 3 and TiO 2 . These results highlight the potential of green-processed composites in advanced oxidation processes for wastewater treatment. Graphic abstract