Facile Synthesis of Anatase–Rutile Diphase N-doped TiO2 Nanoparticles with Excellent Visible Light Photocatalytic Activity

Abstract

To further boost the charge separation and photocatalytic activity of TiO2 under visible light, the anatase–rutile mixed-phase nitrogen-doped (N-doped) TiO2 nanoparticles were successfully synthesized through a facile one-step calcining procedure using TiN as raw materials. The crystal phases, morphologies, chemical compositions, textural structures, and optical properties of as-obtained N-doped TiO2 were characterized by the corresponding analytical techniques. The photocatalytic activities of as-fabricated samples were evaluated by degrading 4-chlorophenol (4-CP) and methylene blue (MB) aqueous solution under visible light irradiation. The results revealed that the ratio of rutile to anatase increased with the improvement of sintering temperature, and the sample prepared at 500 °C had the best photocatalytic activity. This might be because it possessed the most appropriate rutile/anatase proportion as well as the nitrogen doping. The transient photocurrent responses, photoluminescence spectra (PL) measurements, and active species trapping experiments were implemented to disclose the photocatalytic mechanism. This work will provide a further insight into the synthesis of highly efficient N-doped TiO2 photocatalysts for organic contaminant removal.

Enhanced Photovoltaic Properties of Dye-Sensitized Solar Cells through Ammonium Hydroxide-Modified (Nitrogen-Doped) Titania Photoanodes

“…In addition, the binding energy of N 1s photoelectron highly depends on the method employed to synthesize the Ndoped TiO 2 nanoparticles [35]. In the present study, N 1 s peak observed at 400.7 eV could be attributed to the interstitial N of the N-doped TiO 2 with an O−Ti−N linkage [36] which is also in consistent with the XPS results of N-doped TiO 2 reported by Liu et al [37]. Moreover, the presence of this nitrogen in the N-doped TiO 2 has led to reduction of TiO 2 bandgap as well.…”

Charge Carrier Dynamics in Undoped and N-Doped Titania Nanolayers upon Ultraviolet and Visible Light Irradiation

“…Subsequently, the current approaches a constant value, which describes the permanent flow of charges. The fact that the initial current peak is higher in doped samples is due to the initial excitation of more charge carriers and a better charge separation in samples with higher crystallinity . The higher photocurrent at lower wavelengths is due to the excitation of more charge carriers at higher incident photon energies allowing the direct excitation of electrons from the valence into the conduction band .…”

“…The fact that the initial current peak is higher in doped samples is due to the initial excitation of more charge carriers 40 and a better charge separation in samples with higher crystallinity. 41 The higher photocurrent at lower wavelengths is due to the excitation of more charge carriers at higher incident photon energies allowing the direct excitation of electrons from the valence into the conduction band. 42 TDRS measurements revealed that the population of surface-trapped electrons decreased more strongly in N-doped titania than in pure TiO 2 .…”

Manifestation of the Enhanced Photovoltaic Performance in Eco-Friendly AgBiS2 Solar Cells Using Titanium Oxynitride as the Electron Transport Layer

“…The obtained BET curves showed typical type IV with type H 3 hysteresis loops according to the International Union of Pure and Applied Chemistry (IUPAC) classification for both TiO 2 and TiON samples. This observed characteristic of the samples can be attributed to the presence of interparticle porous structures formed in both bare TiO 2 and TiON. , The obtained pore size distribution curves (BJH) indicated the existence of a narrow distribution of pores in the TiON system, with a mean pore size of ∼9.7 nm (inset of Figure b), while the distribution is relatively broader for bare TiO 2 , with a mean decreased pore size of ∼7.2 nm (inset of Figure a). This represents that TiON can possibly have a stable, homogeneous, and reactive surface, which is much more compatible for the sensitizer deposition interaction.…”