A comparative study of nanometer sized Fe(iii)-doped TiO₂photocatalysts: synthesis, characterization and activity

Abstract

Fe(III)-doped TiO 2 nanoparticles have been prepared in three different ways using inorganic or organic precursors, respectively. Transmission electron microscopic (TEM) structure characterization of the obtained particles reveals that TiO 2 particles with and without the Fe(III) dopant possess the crystal structure of anatase. Cryo-TEM of vitrified samples confirms earlier assumptions that TiO 2 nanoparticles tend to form threedimensional networks in solution. A novel energy transfer mechanism is suggested employing these threedimensional networks as antenna systems which lead to improved photocatalytic activities of the colloidal preparations. The performance of the nanostructured TiO 2 with and without Fe-dopant for the photocatalytic oxidation of methanol producing HCHO is strongly dependent on the preparations and the Fe-content. Fe(III)doped TiO 2 nanoparticles prepared from organic precursors by the novel method (¡2.5 atom% Fe) exhibit a greatly enhanced photocatalytic activity (quantum yield of HCHO up to ca. 15%).

Removal of NOX Using Hydrogen Peroxide Vapor over Fe/TiO2 Catalysts and an Absorption Technique

“…For the diffraction patterns of the Fe-doped TiO2 samples, all diffraction peaks were congruent with TiO2 and no peaks attributable to iron species could be observed in the investigated range. The possible reason was that the Fe atoms had successfully replaced Ti atoms and were incorporated into the crystal framework of the TiO2 lattice due to a similar ionic radius of Fe 3+ (0.69 A) and Ti 4+ (0.745 A) [28,29]. As presented in Table 1, iron species loading also impacted on the crystallite size of the samples significantly.…”

“…The catalyst was heated at 400 °C for 6 h in air to remove impurities. The Fe/TiO2 catalysts were prepared by the co-precipitation method, and the details of the process can be found in [28,54,55]. A calculated amount of Fe(NO3)3•9H2O (98.5% , Sinopharm Chemical Reagent, Shanghai, China) and Ti(SO4)2 (97%, Sinopharm Chemical Reagent, Shanghai, China) (the molar ratios of Fe/Ti were 0.5%, 1%, 2%, and 3%, respectively) were dissolved in ice-cold deionized water and stirred for 1 h, then standard ammonia solution (25%, Sinopharm Chemical Reagent, Shanghai, China) was added slowly to the solution under stirring until the pH rose to 10.…”

Structural, optical, and magnetic study of Ni-doped TiO2 nanoparticles synthesized by sol–gel method

“…[27][28][29][30][31][32][33][34][35]. Sol-gel method is often employed as it offers the advantages such as precise control over the stoichiometry, low-temperature synthesis, high crystallinity, and high purity [36][37][38].…”

Characterization and Photocatalytic Evaluation (UV-Visible) of Fe-doped TiO2 Systems Calcined at Different Temperatures

“…, respectively (16,20,(22)(23)(24). In addition, mixtures of oxides are unlikely because the amount of iron is very small.…”