Enhanced Photocatalytic Degradation of RhB Driven by Visible Light-Induced MMCT of Ti(IV)−O−Fe(II) Formed in Fe-Doped SrTiO3
133
Citation
40
Reference
10
Related Paper
Citation Trend
Abstract:
It is important to reveal the origin of the visible light-induced photocatalytic activity of transition metal-doped SrTiO3 in which an isolated energy level is created by the dopant in the forbidden band gap. In this particle, the photocatalytic and photophysical properties of pure SrTiO3 and Fe-doped SrTiO3 were investigated comparatively. The Fe-doped SrTiO3 has been shown to have a much higher photocatalytic activity than pure SrTiO3 for the degradation of RhB under visible light irradiation. It was showed that doping Fe into SrTiO3 exhibited an absorption extending up to the visible region in the optical absorption spectrum and established the TiIV−O−FeII heterobimetallic linkages in the host. Difference diffuse reflectance spectra revealed that the absorption in the visible region is partly attributed to the metal-to-metal charge-transfer (MMCT) excitation of TiIV−O−FeII linkage formed in the Fe-doped SrTiO3. The visible light excitation of TiIV−O−FeII linkage was demonstrated to be the cause of the enhanced degradation of RhB. Furthermore, it was noted that the TiIV−O−FeII linkages only onto and nearest the surface of the Fe-doped SrTiO3 behavior as active sites for the visible light-induced photocatalysis.Keywords:
Visible spectrum
Visible spectrum
Cite
Citations (40)
The simple synthesis of TiO2 and improved visible-light photocatalytic performance of TiO2 have been the goal of researchers. When compared to pure phase TiO2, mixed-phase TiO2 nanoparticles with oxygen vacancies can aid in lowering the band gap and carrier recombination rate, which improves the performance of visible light photocatalysis. In this study, three different acids were separately applied in the hydrothermal synthesis of TiO2 nanoparticles without any post-heat treatment. The reaction was carried out at a relatively low temperature not exceeding \(140^{\circ}\)C. Under the visible light illumination-assisted photocatalytic degradation of methyl orange in water, the TiO2 nanoparticles obtained from HCl (H-TiO2) and CH3COOH (A-TiO2) showed stable photocatalysis performance for increasing the cycles up to ten times while only five cycles for TiO2 nanoparticles obtained by HNO3-assisted (N-TiO2). Compared with efficiencies of N-TiO2 nanoparticles, H-TiO2 and A-TiO2 showed superior efficiencies and have excellent photocatalytic performances when assisting in the degradation of methyl orange in water under visible light illumination. The high visible-light photocatalytic performance and the simple acid-assisted synthesis of the H-TiO2 and A-TiO2 nanoparticles will promote the industrial application.
Visible spectrum
Methyl orange
Cite
Citations (0)
Visible spectrum
Cite
Citations (51)
Visible spectrum
Cite
Citations (67)
Cite
Citations (60)
Cite
Citations (12)
The process of p-type doping for GaN nanowires is investigated using calculations starting from first principles. The influence of different doping elements, sites, types, and concentrations is discussed. Results suggest that Mg is an optimal dopant when compared to Be and Zn due to its stronger stability, whereas Be atoms are more inclined to exist in the interspace of a nanowire. Interstitially-doped GaN nanowires show notable n-type conductivity, and thus, Be is not a suitable dopant, which is to be expected since systems with inner substitutional dopants are more favorable than those with surface substitutions. Both interstitial and substitutional doping affect the atomic structure near dopants and induce charge transfer between the dopants and adjacent atoms. By altering doping sites and concentrations, nanowire atomic structures remain nearly constant. Substitutional doping models show p-type conductivity, and Mg-doped nanowires with doping concentrations of 4% showing the strongest p-type conductivity. All doping configurations are direct bandgap semiconductors. This study is expected to direct the preparation of high-quality GaN nanowires.
Wide-bandgap semiconductor
Cite
Citations (28)
Doping strategy has been applied in lots of areas holding promising performance for many functions. Here, we systemically report the main trends in structural, electronic properties and chemical bonding for V doped into 2H-NbSe2 in two types of doping by means of the first-principles PBE-GGA calculations. To investigate the stability of the doped system with changing concentration of V atoms, 2 × 2 × 1, 3 × 3 × 1 and 4 × 4 × 1 2H-NbSe2 supercells have been taken into consideration. Results show that it is easier to be doped as the concentration of dopant V is lower and the substituted doping structure is more stable than that of the dopant embedded into the interlayer. In addition, it is found that the dopant V atom forms a covalent bond with the surrounding Se atoms in both of the two doping structures, which can explain the variations of the structural parameters after V atom is doped into 2H-NbSe2. Moreover, what leads to the variation of the electronic structures is that the asymmetric structure and the more energetic Se atoms firstly near the dopant V atom after V is doped into 2H-NbSe2 in both of the two doping types. Our calculation results can provide good theoretical knowledge for the subsequent experiments.
Cite
Citations (20)
As well as understanding the location of dopants in optical materials, it is also important to understand how much dopant can be added to a given material. A method for calculating the maximum concentration of dopants has been developed, and applied to dopants in mixed metal fluorides for optical and nuclear clock applications. Applications to rare earth doping in YLiF4, and Th doping in LiCaAlF6/LiSrAlF6 are described, and compared with available experimental data.
Cite
Citations (0)