Ab initio studies of Nb–N–S tri-doped TiO2 with enhanced visible light photocatalytic activity

Ren, Dahua; Cheng, Junxia; Cheng, Xinlu

doi:10.1016/j.jssc.2016.03.020

Cited by 9 publications

(4 citation statements)

References 40 publications

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“…Besides, TiO 2 powder is difficult to separate in the catalytic process and recycle, so the composite modification to TiO 2 is a hot spot in the research of photocatalytic materials . The reformative methods have been come up such as coupling with semiconductor, surface photosensitization, doping metal, doping non‐metal and co‐doping . Due to the secondary pollution of metal doping, the use of non‐metal as surface photosensitization modifier or non‐metal doping is more environmentally friendly.…”

Section: Introductionmentioning

confidence: 99%

Fabrication and Characterization of N−TiO₂/C/ATP Composite with Enhanced Visible‐Light Photocatalytic Performance for the Degradation of Polyacrylamide in Wastewater

et al. 2020

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A novel N−TiO2/C/attapulgite (N−TiO2/C/ATP) composite photocatalyst was prepared by sol‐gel method using ATP supported o‐phenanthroline modified TiO2. The as‐prepared samples were characterized by X‐ray diffraction (XRD), fourier transform infrared (FT‐IR), X‐ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), ultraviolet‐visible diffuse reflectance spectroscopy (UV‐vis DRS) and N2 adsorption–desorption measurements. The activity of these photocatalysts was tested by degrading polyacrylamide (PAM) under visible light irradiation while N−TiO2/C/ATP shows significant photocatalytic enhancement compared to pure TiO2. The optimal ratio of N−TiO2/C/ATP photocatalyst is n (TiO2): n (o‐phenanthroline)=20 : 1 and the m (N−TiO2/C): m (ATP)=1 : 1. When the initial concentration of PAM is 300 mg/L and the catalyst dosage is 1.5 g/L, the removal rate of chemical oxygen demand (COD) reaches 86.3 % at pH 2 under 2 h of visible light. The enhanced performance can be attributed to the C element in o‐phenanthroline is modified on the TiO2 surface as a surface sensitizer and the N element may enter anatase TiO2 lattice and replace to form O−Ti−N bond. Meanwhile, some TiO2 particles were permeated into the layer of ATP, which made the composite photocatalyst more stable and the N−TiO2/C/ATP composite exhibits good stability after three times recycling. In addition, the possible photocatalytic mechanism is proposed at the end.

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Section: Introductionmentioning

confidence: 99%

Fabrication and Characterization of N−TiO₂/C/ATP Composite with Enhanced Visible‐Light Photocatalytic Performance for the Degradation of Polyacrylamide in Wastewater

et al. 2020

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“…modelled transition‐metal ions implanted into TiO 2 bulk, using the full‐potential linearized augmented plane‐wave (FP LAPW) method, and found that the 3 d states of V, Cr, and Fe ions play a key role for the redshift of the ultraviolet‐visible absorption spectrum . DFT+ U studies of Nb−N−S tri‐doped anatase within the GGA approach and PBE exchange‐correlation functional have shown that the mixture of new N(2 p ) and S(3 p ) states on the top of the valence band, as well as the Nb(4 d ) states in the bottom of conduction band, reduce the band gap from 3.2 to 2.0–2.5 eV . Nishikawa et al .…”

Section: Progress In Contemporary Research Of Doped Tio2 Applicabilitmentioning

confidence: 99%

“…It is necessary to formulate a theoretical procedure to predict prudently the electronic structure and the charge redistribution in photocatalysts. A number of simulations performed so far deal mainly with doped and codoped photocatalytic bulk materials,, and their low‐index surfaces, as well as 0D and 1D nanostructures ,. There are two critical issues that are important for photocatalysis, but not yet well treated in conventional density functional theory, as well as other first‐principles packages: 1) the lack of resources, essential for simulations of the strong polarization on the charged electrode surfaces in aqueous electrolyte; and 2) the inaccuracy of existing DFT functionals for a proper alignment of the H + /H 2 and H 2 O/O 2 potentials with the edges of the band gap or the induced dopant levels .…”

Section: Progress In Contemporary Research Of Doped Tio2 Applicabilitmentioning

confidence: 99%

Doped 1D Nanostructures of Transition‐metal Oxides: First‐principles Evaluation of Photocatalytic Suitability

Zhukovskii

Piskunov

Lisovski

et al. 2016

Israel Journal of Chemistry

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The splitting of water molecules under the influence of solar light on semiconducting electrodes is a clean and renewable source for the production of hydrogen fuel. Its efficiency depends on the relative position of the band‐gap edges or the induced defect levels with a proper band alignment relative to the redox H+/H2 and O2/H2O potentials. For example, TiO2 and ZnO bulk, as well as thick slabs (whose band gaps are ∼3.2–3.4 eV), can be active only for photocatalytic applications under UV irradiation (possessing ∼1 % solar energy conversion efficiency). Nevertheless, by adjusting the band gap through formation of nanostructures and further doping, the efficiency can be increased up to ∼15 % (for 2.0–2.2 eV band gap). We analyse results of DFT (density functional theory) calculations on TiO2 nanotubes and ZnO nanowires, both pristine and doped (e.g., by AgZn, CO, FeTi, NO and SO substitutes). To reproduce the energies of one‐electron states better, we have incorporated the Hartree‐Fock (HF) exchange into the hybrid DFT+HF Hamiltonian. Both the atomic and electronic structure of nanomaterials, simulated by us, are analysed to evaluate their photocatalytic suitability, including positions of the redox potential levels inside the modified band gap, the width of which corresponds to visible‐light energies. Analysis of the densities of states (DOS) for considered nanostructures clearly shows that photocatalytic properties can be significantly altered by dopants. The chosen hybrid methods of first‐principles calculations significantly simplify selection of suitable nanomaterials possessing the required photocatalytic properties under solar light irradiation.

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“…Numerous computational studies have been carried out on codoped systems for band gap engineering, ,,− in particular a computational screening by Yan and co-workers found that [Nb + N] and [Ta + N] were ideal at a “high alloying concentration” regime, and that both [Mo + 2N] and [W + 2N] were ideal in a “low alloying concentration” regime. Carbon codoped systems were suggested to reduce the band gap too much, which combined with the problems associated with doping with C mean that reproducibility will be an issue in this context, despite a few promising results. , …”

Section: Introductionmentioning

confidence: 99%

Dispelling the Myth of Passivated Codoping in TiO₂

et al. 2019

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Modification of TiO2 to increase its visible light activity and promote higher performance photocatalytic ability has become a key research goal for materials scientists in the past 2 decades. One of the most popular approaches proposed this as “passivated codoping”, whereby an equal number of donor and acceptor dopants are introduced into the lattice, producing a charge neutral system with a reduced band gap. Using the archetypal codoping pairs of [Nb + N]- and [Ta + N]-doped anatase, we demonstrate using hybrid density functional theory that passivated codoping is not achievable in TiO2. Our results indicate that the natural defect chemistry of the host system (in this case n-type anatase TiO2) is dominant, and so concentration parity of dopant types is not achievable under any thermodynamic growth conditions. The implications of passivated codoping for band gap manipulation in general are discussed.

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Ab initio studies of Nb–N–S tri-doped TiO2 with enhanced visible light photocatalytic activity

Cited by 9 publications

References 40 publications

Fabrication and Characterization of N−TiO₂/C/ATP Composite with Enhanced Visible‐Light Photocatalytic Performance for the Degradation of Polyacrylamide in Wastewater

Fabrication and Characterization of N−TiO₂/C/ATP Composite with Enhanced Visible‐Light Photocatalytic Performance for the Degradation of Polyacrylamide in Wastewater

Doped 1D Nanostructures of Transition‐metal Oxides: First‐principles Evaluation of Photocatalytic Suitability

Dispelling the Myth of Passivated Codoping in TiO₂

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Ab initio studies of Nb–N–S tri-doped TiO2 with enhanced visible light photocatalytic activity

Cited by 9 publications

References 40 publications

Fabrication and Characterization of N−TiO2/C/ATP Composite with Enhanced Visible‐Light Photocatalytic Performance for the Degradation of Polyacrylamide in Wastewater

Fabrication and Characterization of N−TiO2/C/ATP Composite with Enhanced Visible‐Light Photocatalytic Performance for the Degradation of Polyacrylamide in Wastewater

Doped 1D Nanostructures of Transition‐metal Oxides: First‐principles Evaluation of Photocatalytic Suitability

Dispelling the Myth of Passivated Codoping in TiO2

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Product

Resources

About

Fabrication and Characterization of N−TiO₂/C/ATP Composite with Enhanced Visible‐Light Photocatalytic Performance for the Degradation of Polyacrylamide in Wastewater

Fabrication and Characterization of N−TiO₂/C/ATP Composite with Enhanced Visible‐Light Photocatalytic Performance for the Degradation of Polyacrylamide in Wastewater

Dispelling the Myth of Passivated Codoping in TiO₂