The influence of calcination temperature on (photo)electrochemical property of TiO₂ prepared by the sol-gel method

Abstract

In this work, titanium dioxide (TiO2) was successfully synthesized via the sol-gel method using Titanium (IV) isopropoxide as a precursor. The mixture was heated to 115°C to obtain the solid powder of TiO2. Ti K-edge XANES measurement was performed to determine its structure. Three pre-edge peaks at energy levels between 5460-5480 eV were clearly observed. These features correlated to 1s→d electronic transition in the distorted-octahedral structure of anatase TiO2. The in situ XANES experiment at 700°C revealed no phase transformation from anatase to rutile. There was no characteristic of the rutile phase on the XRD pattern of TiO2 calcined at 700°C. This result confirmed the stability of anatase. SEM images revealed the circular shape of TiO2 particles with a diameter of around 50 nm. The highest (photo)electrochemical activity of TiO2 was obtained at the calcination temperature of 300°C as investigated by a cyclic voltammetry.

The Influence of the Precursor’s Nature and Drying Conditions on the Structure, Morphology, and Thermal Properties of TiO2 Aerogels

“…To determine whether the exothermic peak at 368-474 • C in the DTA curves was induced by the formation of the anatase phase, several samples were heat-treated at 500 • C for two hours. This temperature was chosen based on data from the literature [41] and the obtained results (Figure 7, Table 2) are as follows: the anatase phase is formed at a temperature higher than 400 • C. Moreover, the selected calcination temperature must ensure full thermal conversions in the mentioned temperature range. To confirm this, the calcinated samples were investigated by XRD analyses (Figure 8).…”