Synergistic effects of Co-Ni nanoalloys on SiO\(_{2}\)@TiO\(_{2}\): A novel approach to photocatalytic tetracycline degradation

To develop a cost-effective alternative to noble metal catalysts for photocatalysis, we synthesized a series of bimetallic Co-Ni nanoalloys on core-shelled SiO2@TiO2 nanostructures via a chemical reduction approach. The research demonstrates the photocatalytic behaviour of the Co-Ni alloy-enhanced SiO2@TiO2 (ST-Co, Ni) hybrid nanocatalyst, focusing on its crystalline structures, morphological shapes, chemical conditions, and optical properties, utilizing techniques such as X-ray diffraction, field emission scanning electron microscopy, UV-visible diffuse reflectance spectroscopy, photoluminescence spectroscopy, transmission electron microscope, and electrochemical analysis. The catalyst was evaluated for its effectiveness in degrading tetracycline, an overused antibiotic that persists in aquatic environments and is known for negatively impacting water quality. The Co-Ni nanoalloys were tested in various ratios (1:1, 1:2, 2:1), with the 1:1 ratio (ST-Co, Ni1:1) emerging as the most effective, achieving a degradation rate of 88.4% at pH 5 in 120 min. This optimal catalyst demonstrated superior charge carrier separation and enhanced absorption of solar radiation in the visible spectrum. Improved solar light absorption and surface plasmon resonance work in concert to promote effective charge transfer from the nanoalloys to the titania, which is probably the cause of the observed photocatalytic degradation rates. So the proposed hybrid nanocatalyst paves the way for photocatalysis and can be suitable for different photocatalytic processes.