RESUMO
We report the preparation and characterization of a new heterostructured Ag-TiO2/ZnFe2O4 (ATZ) nanocomposite. X-ray diffraction (XRD) reveals the presence of spinel type ZnFe2O4 and anatase TiO2. Scanning electron microscope (SEM) images of ATZ nanocomposites show that Ag nanoparticles are successfully loaded on the composite Ag-TiO2 and is uniformly distributed on surface of ZnFe2O4 forming a nanocomposite with an approximate particle size of 44.8 nm. High-resolution transmission electron microscope (HR-TEM) analysis clearly indicates the particles with spherical and hexagonal structure and sizes of most of the particles are below 50 nm. Ultra violet-visible diffuse reflectance spectra (UV-vis-DRS) show that Ag-TiO2/ZnFe2O4 has increased visible absorption than TiO2. Photoluminescence (PL) spectra shows that the intensity of ATZ is low relative to prepared TiO2. The photocatalytic degradation of Reactive Yellow 86 (RY 86) dye was studied. Based on the band gap energies of TiO2 and ZnFe2O4, a mechanism of degradation is given. Photocatalytic activity results suggest that as-prepared ATZ shows higher photodegradation efficiency than pure TiO2. The main reactive oxidative species involved in the degradation and stability of photocatalyst were also investigated. ATZ shows higher electrocatalytic activity than TiO2 for methanol electrooxidation. The cytotoxicity of ATZ was analysed. Multifunctionality of ATZ makes it useful for environmental and biomedical applications.
