Effect of Silver Nanoparticles SILAR Cycle on TiO2 Nanoparticles Thin Film: Optical and Structural Study

Abstract

Titanium dioxide (TiO2) has gained a lot of research interests due to its applicability in electronic materials, energy, environment, health & medicine, catalysis etc as a result of its high permittivity, refractive index, efficiency, low-cost chemical inertness, eco-friendliness, photocatalytic activity, photostability and ability of decomposing a wide variety of organic compounds. In this study, the effect of silver nanoparticles (AgNPs) deposited through Successive Ionic Layer Adsorption and Reaction (SILAR) on the optical, structural and morphological properties of TiO2 was explored systematically. The investigation was achieved via a combined effect of UV-vis spectroscopy, Scanning Electron Microscope (SEM) and X-ray Diffractometer (XRD) characterizing tools. As illustrated from the SEM micrographs, introduction of AgNPs result to enhanced nucleation and films growth with presence of shining surface which can be seen to contribute to good photon management through enhanced light scattering. The XRD results showed that, the presence of AgNPs on TiO2 results to peaks corresponding to that of the TiO2 crystallographic planes with no silver peaks detected due to its low concentration in the nanocomposite which shows that it was just homogeneously distributed on the surface of the TiO2 nanoparticles. The UV-Vis results show a red shift to higher wavelength, showing an increase in visible light absorption which can be ascribed to the strong field effect of the Localized Surface Plasmon Resonance (LSPR). There was a decrease in band gap edge with introduction of AgNPs which indicated an increase in the optical conductivity of the AgNPs modified film.