A study on titanium dioxide nanoparticles synthesized from titanium isopropoxide under SILAR-induced gel method: Transition from anatase to rutile structure

Successive ionic layer adsorption and reaction (SILAR)-induced gelling method was adopted in synthesizing titanium dioxide nanoparticles, annealed at various temperatures so as to investigate their morphological, structural, optical, elemental, chemical bond and photoluminescence properties. Characterizations of the as-prepared nanoparticles were carried out using scanning electron microscope (SEM), X-ray diffractometer (XRD), transmission electron microscopy (TEM), selected area electron diffractometer (SAED), energy dispersive X-ray spectroscopy (EDX), UV–Visible spectrophotometer (UV–Vis), photoluminescence (PL) and fourier transform infrared (FTIR) spectroscopies. Nanospherical balls revealing anatase and rutile crystal structures at (1 0 1) and (1 1 0) planes respectively were observed. Agglomerations of chain-like small particles manifested in Debye-Scherrer′s rings were evident from the TEM and SAED patterns. EDX spectra revealed deposition of the major elemental constituents: Ti and O. High transmittance of about 80% with a band gap energy ranges for the anatase and rutile phases was obtained from the optical properties. Emission peaks arising from the PL spectra gave information on the charge transport and recombination rates occurring at the TiO₂ nanoparticles while FTIR studies revealed the chemical vibrational bonds of the deposited TiO₂ NPs. The obtained results make the deposited nanoparticles suitable for solar cell applications.