Influence of surfactant on sol-gel-prepared TiO2: characterization and photocatalytic dye degradation in water

Abstract

In this study, Titanium dioxide (TiO2) nano-powder was prepared using a sol-gel process with and without surfactant. A typical non-ionic surfactant (Triton X-100) was used during the process. The phase compositions of TiO2 and surfactant-assisted TiO2 (TiO2-sa) were investigated by FTIR, X-ray diffraction (XRD), scanning electron microscope-energy dispersive spectroscopy (SEM-EDS), and thermogravimetric analysis (TGA). Brunauer–Emmett–Teller (BET) was used to determine the nano-powder’s specific surface area and pore size distribution. Moreover, transmission electron microscopy (TEM) and selected area electron diffraction (SAED) analysis exhibited particle size in the range of 65–85 nm and polycrystalline phase, respectively. UV-vis spectrophotometer showed high absorption as dominating the visible region (438–450 nm) with relative redshift and reduced bandgap from 2.98 to 3.12 eV upon adding surfactant on TiO2. X-ray fluorescence spectroscopy (XRF) exhibits high purity TiO2 with more than 82% composition with the lowest relative standard deviation (RSD %). Moreover, the photoluminescence (PL) of TiO2-sa showed enhanced oxygen vacancies and surface defects which reduce the direct electron-photon (e/h+) pair recombination. TiO2-sa illustrated promising characteristic features of an active photocatalyst for the degradation of organic pollutants.