Effect of Anatase/Rutile Phase Ratio on the Photodegradation of Methylene Blue under UV Irradiation

Abstract

Titanium dioxide (TiO2) is known as one of the widely used catalysts in photocatalysis process. Recently, the photocatalysis of TiO2 has been implied in water purification and treatment, particularly dyes and organic compounds degradations. Naturally, the TiO2 can be found in three phases including anatase, rutile and brookite; each phase has its own specific properties such as grain size, stability and band gap energy. In this work, the effect of calcination temperature on the structure, morphology and photocatalytic activity were investigated. The data suggested that the anatase/rutile ratio of TiO2 can be controlled through the calcination process. The phase transformation data strongly indicated the liner function between percentage of rutile phase and calcination temperature. The BET analysis provided the consistent data with XRD patterns by showing that the specific surface area was decreased by increasing calcination temperature. The photodegradation of methylene blue under UV irradiation proved that the mixed phase of anatase/rutile ratio at 78.5/21.5 provided the highest photocatalytic activity. The phase composition ratio can influence the nanoparticles properties including band gap, specific surface area and energy band structure. Therefore, the control of anatase/rutile ratio was an alternative to enhance the photocatalytic activity of TiO2 nanoparticles for dyes and organic compounds degradations.

Heterophase Polymorph of TiO2 (Anatase, Rutile, Brookite, TiO2 (B)) for Efficient Photocatalyst: Fabrication and Activity

“…Rutile is the most stable form compared to the other two forms that are metastable, brookite, and, anatase so at high temperatures it will turn into rutile [ 246 ]. It is common to regulate the calcination temperature to produce TiO 2 with a mixture of anatase and rutile phases [ 247 , 248 , 249 , 250 , 251 ]. However, there are also other factors that can be used to control the appearance of these two phases such as the pH and the solvent used [ 252 , 253 ].…”

“…Table 3 shows the performance of anatase/rutile photocatalytic degradation for the organic pollutants. Photocatalytic activity against the degradation of organic compounds is carried out by adding photocatalysts to the solution of organic compounds; then, concentration reduction was observed with a UV–vis spectrophotometer [ 247 ], or by measuring the conductivity of CO 2 resulting from degradation [ 248 ]. For hydrogen generation, the hydrogen formation is measured with gas chromatography (GC) [ 249 ].…”

Ag/GO/TiO2 nanocomposites: the role of the interfacial charge transfer for application in photocatalysis

“…rutile single phase. The phase composition can affect the nanoparticle properties including band gap, SSA and energy band structure [47]. In addition, the TiO 2 nanoparticles in the anatase phase also had a high capacity to photodegrade the dye (76%).…”

“…To evaluate the efficiency of these nanocomposites, rhodamine B (Rh B) was used as a model molecule. The choice to perform the photocatalytic test with rhodamine B is related to the greater stability of this molecule to hydroxyl radicals compared to MB [47]. The presence of GO in the samples was effective in increasing the degradation of the rhodamine B dye.…”

Ti-Modified Hydroxyapatites: Synthesis, Crystal Chemistry, and Photocatalytic Activity

“…However, the detection of impurity phases at low contents or in the amorphous state is often beyond the sensitivity of PXRD. The impurity phases forming in Ti-containing media are often represented by titanium oxides. − Both anatase and rutile modifications of TiO 2 (especially anatase) are well known for their photocatalytic properties and their presence might lead to photocatalytic activity of the HAp/TiO 2 composites and mixtures. In some cases, the formation of titanium oxides manifests itself only after thermal treatment, which causes crystallization of amorphous titanium species and makes them detectable for XRD.…”