Synthesis and characterization of nitrogen-doped TiO2 nanoparticles prepared by sol–gel method

Abstract

The N-doped TiO2 has been synthesized by\ud sol–gel method, using titanium isopropoxide, isopropanol\ud and an aqueous solution of ammonia with ratio 2:1:10. The\ud concentrations used for the NH3 aqueous solution were 3,\ud 7, 10 and 15 %. The samples have been analysed by X-ray\ud diffraction, electron microscopy (SEM and TEM) thermogravimetric\ud analysis (TGA), differential scanning calorimetry\ud (DSC), micro-Raman spectroscopy and diffuse\ud reflectivity. TEM, SEM, DSC and TGA showed that the\ud morphology is influenced by the presence of N3- ions but\ud not by the concentration of the solution. Instead reflectance\ud gave us a relation between values of the energy gap and the\ud concentration of N3- ions: the gap between valence and\ud conduction band lowers as the concentration of NH3 in the\ud starting solution increases. From these results we can say\ud that the properties of the material have been tuned by\ud doping with nitrogen ions because the particles absorb\ud more light in the visible range, and this is important for\ud photovoltaic and photocatalytic applications

Enhancement of TiO2 NPs Activity by Fe3O4 Nano-Seeds for Removal of Organic Pollutants in Water

“…In this step the oxidation of the 2-propanol adsorbed on the surface occurred [28]. The drastic difference in the intensity signals indicates a different amount of solvent that increased from sample A to D. Indeed, this result agree well with the surface area analysis from BET isotherms (Table 1), where the increased value of the surface to mass ratio from A to D, implies an increment of the possibility to adsorb the solvent.…”

Sorbents Coupled to Solar Light TiO2-Based Photocatalysts for Olive Mill Wastewater Treatment

“…Ar was used for ZY, while N 2 was used for all other materials. (Figure 1(a)), while the N-doped ones form lamellar isolated aggregates (Figure 1(b)), in accordance with literature [26]. The TiO 2 nanoparticles supported by the zeolite are round shaped (Figure 2) and the sample is homogenous, as previously reported by Maraschi et al [27].…”

“…The DRS spectra of doped and undoped TiO 2 are shown in the supplementary information ( Figure S2). The gap calculation was made according to literature [26,28]. The composite material, TiO 2 @ZY, shows the highest surface area (>200 m 2 g −1 ); the smaller energy gap and higher surface area compared to pristine ZY confirm the successful immobilization of the photocatalyst onto the zeolitic structure.…”

Influence of Fe/C codoped on structural, optical, and photocatalytic properties of TiO2 powders by sol‐gel method

“…However, TiO 2 powders showed a band gap of about 3.2 eV and made it active only in the ultraviolet (UV) range . During the past decades, many effective methods have been implemented to overcome this problem and active TiO 2 in the large absorption area in the UV–Vis spectra, such as doping modification, dye sensitization, and semiconductor compound, which were conducive to improve the photocatalytic performance of TiO 2 . Among these ways, doping is a direct method to change the material structure without complex process, and further remarkably adjust the surface morphology and optical properties of TiO 2 .…”

“…[7] During the past decades, many effective methods have been implemented to overcome this problem and active TiO 2 in the large absorption area in the UV-Vis spectra, such as doping modification, dye sensitization, and semiconductor compound, which were conducive to improve the photocatalytic performance of TiO 2 . [8][9][10][11] Among these ways, doping is a direct method to change the material structure without complex process, and further remarkably adjust the surface morphology and optical properties of TiO 2 . Due to the similar ionic radius between Fe 3+ (0.064 nm) and Ti 4+ (0.061 nm), Ti 4+ was easy to be replaced by Fe 3+ and further changed the properties of TiO 2 .…”