Effect of annealing temperature on structural, optical, and photocatalytic properties of titanium dioxide nanoparticles

Abstract

Titanium dioxide (TiO 2 ) nanoparticles (NPs) were produced by simple sol-gel technique and annealed for 2 h in air. The impact of annealing temperature on the physical, morphological, photocatalytic, and optical properties was studied. X-ray diffraction (XRD) measurements proved that a gradual phase change from anatase to rutile occurred with increased annealing temperature. The crystal structures of the NPs were found to change at different temperatures; anatase phase at 450 °C, mixed-phase (anatase/Rutile) at 550–650 °C, and rutile phase at 750 °C. The rise in the annealing temperature improved the crystallinity of the NPs. The crystal and grain size of the NPs increased with the annealing temperature hence reducing the specific surface area due to the condensed boundaries between subunits of the NPs. As per the Kubelka-Munk equation, the bandgap reduced as the temperature elevated. The photocatalytic activity of the NPs was higher in the anatase/rutile mixed-phase than in the single anatase and rutile phase. Experimental results indicated that annealing temperature could effectively change the properties of the TiO 2 NPs.

Inverse and distorted Co2SnO4 cubic spinel thin films for dimethylamine detection at room temperature

“…A prepared thin film at 450 °C discloses a weak and broad hump, which possesses the mixed phase of Co 3 O 4 (2 θ = 19.03° & 36.75°) and SnO 2 (2 θ = 26.78° & 38.17°) crystal structure. In the temperature range of 600 to 1000 °C, due to the low crystalline growth, mixed phases like Co 3 O 4 , SnO 2 , Co 2 SnO 4 have been observed 60,61 and are clearly seen in Fig. 1(a).…”

Effect of nickel doping concentration on the morphological and structural properties of titanium dioxide nanoparticles

“…The XRD data were recorded by scanning 2θ from 20° to 90°. The crystallite size (D) for TiO 2 and doped TiO 2 samples were calculated by using the Debye-Scherrer formula from the XRD analysis [15,18] as shown in Equation ( 1). This equation is a well-known method for calculating the crystallite size based on the line broadening for the XRD peaks at their full width at half maximum (FWHM).…”

Improved Photoactivity Of NiO/ZnO Nanorods Heterostructured Films Relying On Scaffold Surface Cleaning And NiO Deposition Time Optimization

“…Contradictory opinions on the role of oxygen vacancies in the catalytic processes have been reported [10–12] . Previous works on reference TiO 2 n‐type photocatalysts have revealed that the photocatalytic activity can be enhanced by increasing the concentration ratio of surface defects to bulk defects by annealing [13,14] or by doping [15,16] …”

“…[8,9] Contradictory opinions on the role of oxygen vacancies in the catalytic processes have been reported. [10][11][12] Previous works on reference TiO 2 n-type photocatalysts have revealed that the photocatalytic activity can be enhanced by increasing the concentration ratio of surface defects to bulk defects by annealing [13,14] or by doping. [15,16] Likewise, choosing the right morphology plays a crucial role in structural stability and photocatalytic activity, influencing the preferential charge localization and transfer rate.…”