Increased two-photon reverse saturable absorption in ZnO/TiO2 core/shell nanocomposites

In this study, ZnO cores were first synthesized by using procedures zinc acetate dehydrate and sodium hydroxide via a co-precipitation method. Then, TiO2 shells were coated on the ZnO nanoparticles by using TTIP through co-precipitation approach to form ZnO/TiO2 core/shell nanocomposites. Structural and elemental studies were performed by X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). Nanostructure morphologies were analyzed by field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The optical absorption edges and band-gap energies were calculated using UV-vis spectra. Open-aperture z-scan technique was finally used to survey two-photon absorption phenomenon. Obtained results showed an increase in two-photon reverse saturable absorption for the ZnO/TiO2 core/shell nanocomposites compared to pristine ZnO nanoparticles.