Synthesis of iron-doped TiO2 nanoparticles by ball-milling process: the influence of process parameters on the structural, optical, magnetic, and photocatalytic properties

Abstract

Titanium dioxide (TiO 2) absorbs only a small fraction of incoming sunlight in the visible region thus limiting its photocatalytic efficiency and concomitant photocatalytic ability. The large-scale application of TiO 2 nanoparticles has been limited due to the need of using an ultraviolet excitation source to achieve high photocatalytic activity. The inclusion of foreign chemical elements in the TiO 2 lattice can tune its band gap resulting in an absorption edge red-shifted to lower energies enhancing the photocatalytic performance in the visible region of the electromagnetic spectrum. In this research work, TiO 2 nanoparticles were doped with iron powder in a planetary ball-milling system using stainless steel balls. The correlation between milling rotation speeds with structural and morphologic characteristics, optical and magnetic properties, and photocatalytic abilities of bare and Fedoped TiO 2 powders was studied and discussed.

Photocatalytic fabrics based on reduced graphene oxide and TiO2 coatings

“…Anatase and rutile have identical chemical composition but different crystal systems and thus, their isoelectric point (IEP) occurs at different pH values, 4.7 vs. 6.2, respectively. The isoelectric pH value was found to be ∼5.2 [60]. This is an acceptable value since it reflects the effect of the mixture of the two crystalline phases.…”

“…From Fig. S3 it is possible to observe that for pH > 5 the TiO 2 particles present negative -potential values that evidence the negative nature of its surface electrical charges, which also contributes for the TiO 2 suspension stability via the appearance of repulsive electrostatic forces (Coulomb forces) [60]. TiO 2 also presents negative charges since the pH of the TiO 2 solutions (5 g L −1 ) employed was near to 6.…”

Comparative study of (N, Fe) doped TiO2 photocatalysts

“…In fact, when Fe is located in the surface of nanoparticles (when solubility limit is overcome), a superparamagnetic behavior is observed as a result of the formation of clusters of nanoparticles of metallic Fe or Fe oxides in the surface [50]. However, when Fe is located in the surface, an improvement of the photocatalytic activity is usually detected due to the enhancement of the transferring of electron/holes pairs to the substrate which is adsorbed in the surface of photocatalyst [51].…”

Deposition of Photocatalytic TiO2 Coating by Modifying the Solidification Pathway in Plasma Spraying

“…The absorbance edge is ascribed to the charge transfer from the valence band to the conduction band. For TiO 2 materials, the valence band is largely caused by 2p orbitals of the oxide anions, and the conduction band is constituted with 3d t 2g orbitals of the Ti 4+ cations [23]. These charge carriers present high reactive activity and can act with different paths.…”