Influence of sound and calcination temperature on the fabrication of TiO2-based photocatalysts and their photoactivity for H2 production

Abstract

This work evaluates the influence of sound and calcination temperature on the synthesis of TiO2-based photocatalysts and designated IDs as TiO2_473, TiO2_623, TiO2_473HS, TiO2_623HS, TiO2_473QB, and TiO2_623QB. All designated TiO2-based photocatalysts were synthesized using the precipitation technique in the absence and presence of sound (409 and 274 Hz), and calcination at 473 and 623 K. Various instrumental techniques, including Thermogravimetric Analysis (TGA), Adsorption and N2 desorption, X-ray Diffraction (XRD), Diffuse Reflectance Spectroscopy (DRS), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM), were used to thoroughly characterize the as developed TiO2-based photocatalysts. An increase was observed in the relative intensity of the diffraction peaks with the increase in the calcination temperature in the presence or absence of sound. However, at 409 Hz, the larger crystallite size was observed for all tested fractions. Furthermore, the increase in the calcination temperature promoted the sintering of the mesopores, decreasing total pore volumes and surface area and increasing the average pore diameter. As developed TiO2-based photocatalysts were deployed to produce H2 via reforming an aqueous solution of methanol and ethanol under the UV region. The performance of photocatalysts in the presence of ethanol used as a sacrificial agent in the split of water reaction was unquestionably more relevant than methanol. The following order of H2 production from ethanol was observed, TiO2_473QB > TiO2_473HS > TiO2_623QB > TiO2_623HS > TiO2_473 > TiO2_623.