Ab initio calculations of doped TiO2 anatase (101) nanotubes for photocatalytical water splitting applications

Lisovski, Oleg; Chesnokov, Andrei; Piskunov, Sergei; Bocharov, Dmitry; Zhukovskii, Yuri F.; Wessel, Michael; Spohr, Eckhard

doi:10.1016/j.mssp.2015.09.003

Cited by 21 publications

(14 citation statements)

References 8 publications

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“…Obviously, photocatalytic properties of pristine TiO 2 bulk are not good enough to maintain the process effectively, so there is a need to modify the electronic structure of the material either by defect engineering (e.g., doping) or nanoscale transformation of its morphology. Our theoretical simulations show that pristine anatase-structured titania SWNTs rolled up from both (001) and (101) nanothin sheets possess the band gaps noticeably larger than those of TiO 2 bulk (by several tenths eV) [5,7,9]. On the other hand, the band gaps of doped titania NTs are essentially reduced, down to 2.2 eV in the case of N O +S O codoping of TiO 2 (001) NT [7].…”

Section: Semiconductor Photocatalysis -Materials Mechanisms and Applmentioning

confidence: 79%

“…Possible dimer-type sites for S+N codopants are assigned by additional indexes for identification ( Figure 15: "FR" stands for "front", "B" for "between", "N" for "near" and "UND" for "under"). (Figure 14), in the segment of 6-layer wall of (−12,12) TiO 2 (101) nanotube [9].…”

Section: Concentration Of Defectsmentioning

confidence: 99%

“…The general observation is that in most cases S and N atoms have a tendency to be found closer to each other. Gray column correspond to pristine (−12,12) NTs while green columns from the second to the sixth from the left correspond to (N1-S1)FR, (N1-S1)B, (N2-S1)N, (N3-S1)B, (N4-S1)B and (N4-S1)UND codopants imaged in Figures 14 and 15 [9].…”

Section: Concentration Of Defectsmentioning

confidence: 99%

“…Evaluation of photocatalytic suitability of all titania NTs simulated by us has been performed taking into account their correspondence to band gaps, widths of which are smaller than photon energies in visible light interval while redox levels H + /H 2 and O 2 /H 2 O (−4.44 and −5.67 eV, respectively) are positioned inside these band gaps. This chapter is based on results of our own studies [5][6][7][8][9] as well as theoretical and experimental data available in the literature.…”

Section: Introductionmentioning

confidence: 99%

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First Principle Evaluation of Photocatalytic Suitability for TiO2-Based Nanotubes

Zhukovskii¹,

Piskunov²,

Lisovski³

et al. 2016

Semiconductor Photocatalysis - Materials, Mechanisms and Applications

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Water splitting under the influence of solar light on semiconducting electrodes Immersed in aqueous electrolyte is a potentially clean and renewable source for hydrogen fuel production. Its efficiency depends on relative position of the band gap edges (the visible light interval between infrared and ultraviolet (UV) ranges of electromagnetic spectrum corresponds to gap widths 1.5-2.8 eV) accompanied by a proper band alignment relative to both reduction (H + /H 2) and oxidation (O 2 /H 2 O) potentials (−4.44 eV and −5.67 eV on energy scale for vacuum, respectively) which must be positioned inside the band gap. Its width for TiO 2 anatase-structured bulk is experimentally found to be 3.2 eV, which corresponds to photocatalytic activity under UV light possessing only ~1% efficiency of sunlight energy conversion. Noticeable growth of this efficiency can be achieved by by adjusting the band gap edges for titania bulk through nanoscale transformation of its morphology to anatase-type nanotubes (NTs) (formed by folding of (001) or (101) nanothin TiO 2 sheets consisting of 9 or 6 atomic layers and possessing either (n,0) or (−n,n) chiralities, respectively) accompanied by partial substitution of pristine atoms by C O , Fe Ti , N O and S O single dopants as well as N O +S O codopants. In the latter case, the band gap can be reduced down to 2.2 eV while the efficiency is achieved up to ~15%. The energy differences between the edges of band gap (VB and CB), the highest occupied and lowest unoccupied impurity levels inside the band gap (HOIL and LUIL, respectively) induced in doped NTs, while preserving the proper disposition of these levels relatively to the redox potentials, so that ε VB < ε HOIL < ε O 2 / H 2 O < ε H + /H 2 < ε LUIL < ε CB , thus reducing the photon energy required for dissociation of H 2 O molecule. In this chapter, we analyze applicability of large-scale first principle calculations on the doped single-wall titania NTs of different morphologies with the aim of establishment of their suitability for photocatalytic water splitting.

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Section: Semiconductor Photocatalysis -Materials Mechanisms and Applmentioning

confidence: 79%

Section: Concentration Of Defectsmentioning

confidence: 99%

Section: Concentration Of Defectsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

First Principle Evaluation of Photocatalytic Suitability for TiO2-Based Nanotubes

Zhukovskii¹,

Piskunov²,

Lisovski³

et al. 2016

Semiconductor Photocatalysis - Materials, Mechanisms and Applications

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“…Fe, C, V, and other dopants are possible [4]. Computational modelling of various dopants such as work by Lisovski et al on various atom dopant influence on TiO 2 [37].…”

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confidence: 99%

Nanostructured TiO2-based materials with photocatalytic properties

Knoks¹,

Grīnberga²,

Kleperis³

et al. 2019

Nanostructured Composite Materials for Energy Storage and Conversion: Collection of Articles

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In order to reduce global climate change by limiting CO 2 emissions, it is necessary to switch from continuous power production by burning fossil fuels (coal, oil, gas) to the unsteady energy generation from local renewable energy sources. Wind, sun and rivers are the most popular renewable energy sources, but they are available occasionally or seasonally, which doesn't always coincide with required consumption. It is especially important for countries in Northern latitudes with dark and short days in winter, and sunny, long days in summer, like Latvia. Therefore, reliable energy storage systems are critically needed to store and supply power in continuous manner. Electricity and hydrogen are two comparable energy carriers, and in order to be able to meet humanity's demand for energy storage in the form of electricity and/or hydrogen, appropriate materials are researched [1]. In hydrogen economics, the production of hydrogen from renewables is very important. TiO 2 has attracted high interest of industry and scientific communities. Following the discovery by Honda and Fujishima [2] of TiO 2 photocatalytic properties, it has been used

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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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Ab initio calculations of doped TiO2 anatase (101) nanotubes for photocatalytical water splitting applications

Cited by 21 publications

References 8 publications

First Principle Evaluation of Photocatalytic Suitability for TiO2-Based Nanotubes

First Principle Evaluation of Photocatalytic Suitability for TiO2-Based Nanotubes

Nanostructured TiO2-based materials with photocatalytic properties

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

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