Non-porous Iron Titanate Thin Films Doped with Nitrogen: Optical, Structural, and Photocatalytic Properties

Abstract

The synthesized undoped and nitrogen doped iron titanate films treated at 450 and 500 °C were crystallized forming pseudobrookite and landauite phase as shown by XRD patterns. The presence of urea in the synthesis procedure promoted the crystallization rate. XPS data indicated that iron ions existed in divalent and trivalent forms, and their ratio was changed for nitrogen-doped sample. The formation of the complexes between iron and urea during sol aging with the following reduction of Fe3+ to Fe2+ within calcination can be a reason not only for accumulation of iron onto the surface as shown by EDS but also for twice increase of divalent iron as registered by XPS. The iron titanate films extended the visible light absorption. Two band gap energy values for all iron-contained films were calculated. The photocatalytic response of all iron titanate films treated at 450 °C compared to pure titania films was spectacularly enhanced under UV and visible light. The slight enhance in photocatalytic activity of nitrogen-doped iron titanate films can be explained by the interstitial nitrogen incorporation rather than substitutional.

Effect of Synthesis Conditions of Nitrogen and Platinum Co-Doped Titania Films on the Photocatalytic Performance under Simulated Solar Light

“…Exposure to visible light, efficient photogenerated charge separation through the narrowing of the material's bandgap, or the formation of additional sublevels within the bandgap were studied and still remain the main goal of titania modification [6]. Numerous synthesis approaches have been reported for the manufacturing of active doped titania using single or double doping [6][7][8][9]. Depending on the nature and the concentration of the doping agents, they can act either as charge traps or as recombination sites.…”

Graphite Nanoplatelets Modified with Bimetallic Ni–Fe Particles for Catalysis Purposes

“…It is interaction of carbon dioxide and hydrogen with methane formation. Among the wide variety of catalysts studied in this process the most attention is to Ni-Fe bulk and supported compositions [12][13][14][15][16]. Certainly, the nature of the support significantly affects to an interaction with the active metal, thereby determining the effect on the activity and selectivity of the catalysts in the CO 2 methanation process.…”

Nonporous platinum doped titania films: synthesis, optical and photocatalytic characteristics

“…The non-porous platinum doped titania films were synthesized by sol-gel method [3,7]. To the preliminary cold and acidified (concentrated perchloric acid) ethanol solution, Pt(II) acetylacetonate dissolved in acetone was added.…”

“…It is firstly reported the application of platinum(II) acetylacetonate as a platinum source in the films synthesis owing to some reasons: i) divalent platinum can be reduced or oxidized depending on the goal of the investigation; ii) the presence of divalent platinum in the structure of the semiconductor can act as the active trapping sites for a photogenerated charge; iii) acetylacetonate as a counter ion can be easily involved in the organic network of titania sol causing the sufficient incorporation the doping agent ions into titania lattice and iv) exclude the influence of chloride ions in photocatalytic reactions [3] contrary to the chloroplatinic acid use. Additionally, the creation of multilayered films induced by the gradual crystallization of every layer at 300 °C results in the change of optical, structural and photocatalytic properties of nanomaterials [7].…”

“…There are some main strategies to improve the photocatalytic activity under UV and visible light utilization of TiO2: i) coupling with different semiconductors (TiO2/Fe2O3, TiO2/CdS, TiO2/RuO2, iron titanates), ii) combining with noble metals TiO2/Au, TiO2/Ag, TiO2/Pt), and iii) doping with metal ions and/or non-metals (TiO2/N, TiO2/Fe 3+ /N, TiO2/Zr 4+ /N etc.) [1][2][3][4][5][6][7].…”