Novel Ag–TiO2/ZnFe2O4 Nanocomposites for Effective Photocatalytic, Electrocatalytic and Cytotoxicity Applications

Abstract

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.