Electronic structure and optical properties of TeO2 polymorphs

Moufok, Samira; Kadi, Lamine; Amrani, B.; Khodja, Kouider Driss

doi:10.1016/j.rinp.2019.102315

Cited by 26 publications

(26 citation statements)

References 19 publications

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“…We therefore consider it likely that the increasing amount of Te(0) from KNbTeO 6 to CsNbTeO 6 is the reason for the increasing absorption of visible light. The band gaps of the different TeO 2 polymorphs have been calculated to be approximately 3 eV …”

Section: Resultsmentioning

confidence: 99%

“…The band gaps of the different TeO 2 polymorphs have been calculated to be approximately 3 eV. 44 The oxygen 1s spectra (Figure 6, top) consist of three different signals with mean values of 529.9, 531.1, and 532.9 eV. The 529.9 eV value can be assigned to metal oxide lattice oxygen (magenta), whereas the highest 532.9 eV value belongs to adsorbed water on the surface (purple).…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

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Photoinduced Defect and Surface Chemistry of Niobium Tellurium Oxides ANbTeO₆ (A = K, Rb, Cs) with Defect-Pyrochlore Structure

2020

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The niobium tellurium oxides ANbTeO6 with varying A cations (A = K, Rb, Cs) and defect-pyrochlore crystal structure were used to investigate the effect of A on crystal-structure deformation and defect-chemistry. We show that the light absorption of these compounds in visible light is due to defects and not the effect of a low band gap. Using the materials in photocatalytic hydrogen generation, the prevailing defects and the surface composition change significantly during photocatalytic hydrogen evolution.

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Section: Resultsmentioning

confidence: 99%

Section: ■ Experimental Sectionmentioning

confidence: 99%

Photoinduced Defect and Surface Chemistry of Niobium Tellurium Oxides ANbTeO₆ (A = K, Rb, Cs) with Defect-Pyrochlore Structure

2020

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“… 12 − 14 α-TeO 2 displays an indirect band gap of around 2.9 eV and a direct band gap of around 3.3 eV. 15 β-TeO 2 displays only a direct band gap of around 2.2 eV, while γ-TeO 2 only exhibits an indirect band gap of around 3.1 eV. 15 That is why TeO 2 is also used in fiber optics and waveguide applications.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of “Naked” TeO₂Nanoparticles for Biomedical Applications

et al. 2022

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Chalcogenide nanoparticles have become a very active field of research for their optoelectronic and biological properties. This article shows the production of tellurium dioxide nanoparticles (TeO 2 NPs) by pulsed laser ablation in liquids. The produced nanoparticles were spherical with a diameter of around 70 nm. The energy band gap of those nanoparticles was determined to be around 5.2 eV. Moreover, TeO 2 NPs displayed a dose-dependent antibacterial effect against antibiotic-resistant bacteria such as multidrug-resistant Escherichia coli (MDR E. coli ) and methicillin-resistant Staphylococcus aureus (MR S. aureus ). The “naked” nature of the nanoparticle surface helped to eradicate the antibiotic-resistant bacteria at a very low concentration, with IC50 values of ∼4.3 ± 0.9 and 3.7 ± 0.2 ppm for MDR E. coli and MR S. aureus , respectively, after just 8 h of culture. Further, the IC50 values of the naked TeO 2 NPs against melanoma (skin cancer) and healthy fibroblasts were 1.6 ± 0.7 and 5.5 ± 0.2 ppm, respectively, for up to 72 h. Finally, to understand these optimal antibacterial and anticancer properties of the TeO 2 NPs, the reactive oxygen species generated by the nanoparticles were measured. In summary, the present in vitro results demonstrate much promise for the presently prepared TeO 2 NPs and they should be studied for a wide range of safe antibacterial and anticancer applications.

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“…Attempts to identify, propose, and discover new cathode materials in rechargeable aluminum batteries with high performance and capability are more important. Tellurium dioxide (TeO 2 ) mainly exists in two different forms: the colorless tetragonal α-TeO 2 phase (paratellurite) and the yellow orthorhombic β-TeO 2 phase (tellurite). , Most of the information regarding the reaction chemistry has been focused on α-TeO 2 . TeO 2 has attracted much interest owing to its high chemical stability, elastic and optical properties, good electrical conductivity, and anticorrosion behavior, which makes it suitable for various applications. − Notably, it has been applied as an effective electrode material for Li-ion batteries owing to its high specific capacity and cycling stability. , Moreover, researchers have demonstrated that a modified separator with a thin and highly conductive layer was constructed owing to it possessing good electrical conductivity and a large pore volume, thus significantly improving the capacities of the battery. − …”

Section: Introductionmentioning

confidence: 99%

“…Tellurium dioxide (TeO 2 ) mainly exists in two different forms: the colorless tetragonal α-TeO 2 phase (paratellurite) and the yellow orthorhombic β-TeO 2 phase (tellurite). 25,26 Most of the information regarding the reaction chemistry has been focused on α-TeO 2 . TeO 2 has attracted much interest owing to its high chemical stability, elastic and optical properties, good electrical conductivity, and anticorrosion behavior, which makes it suitable for various applications.…”

Section: ■ Introductionmentioning

confidence: 99%

Coral-Like TeO₂ Microwires for Rechargeable Aluminum Batteries

Wang

Luo

et al. 2020

ACS Sustainable Chem. Eng.

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Recently, aluminum-ion batteries have been receiving growing attention based on their low cost, good safety, and excellent capacity. In this work, the coral-like TeO 2 microwires synthesized by two-step thermal treatment can be revealed as excellent aluminum-ion battery cathodes. It delivers a capacity of 214.2 mAh g −1 and a relatively high-voltage plateau of ∼1.3 V at 200 mA g −1 and remains at 88.5 mAh g −1 over 100 cycles. Moreover, the reaction mechanism of TeO 2 is verified as the insertion of Al 3+ ions during discharging. More importantly, based on the design of acetylene black-modified separator, the higher reversible capacity of 152.0 mAh g −1 can be achieved over 150 cycles at 200 mA g −1 with a high Coulombic efficiency of 98.4%. At a higher current density of 500 mA g −1 , the battery can reach a stable capacity of 91.1 mAh g −1 over 700 cycles, displaying the superior long-term cycling stability, high capacity, and good rate capability. The results indicate that the coral-like TeO 2 microwires and acetylene black-modified separator can open up a new opportunity and be of great significance for further development of highcapacity and high-stability aluminum-ion batteries.

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Electronic structure and optical properties of TeO2 polymorphs

Cited by 26 publications

References 19 publications

Photoinduced Defect and Surface Chemistry of Niobium Tellurium Oxides ANbTeO₆ (A = K, Rb, Cs) with Defect-Pyrochlore Structure

Photoinduced Defect and Surface Chemistry of Niobium Tellurium Oxides ANbTeO₆ (A = K, Rb, Cs) with Defect-Pyrochlore Structure

Synthesis of “Naked” TeO₂Nanoparticles for Biomedical Applications

Coral-Like TeO₂ Microwires for Rechargeable Aluminum Batteries

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Electronic structure and optical properties of TeO2 polymorphs

Cited by 26 publications

References 19 publications

Photoinduced Defect and Surface Chemistry of Niobium Tellurium Oxides ANbTeO6 (A = K, Rb, Cs) with Defect-Pyrochlore Structure

Photoinduced Defect and Surface Chemistry of Niobium Tellurium Oxides ANbTeO6 (A = K, Rb, Cs) with Defect-Pyrochlore Structure

Synthesis of “Naked” TeO2Nanoparticles for Biomedical Applications

Coral-Like TeO2 Microwires for Rechargeable Aluminum Batteries

Contact Info

Product

Resources

About

Photoinduced Defect and Surface Chemistry of Niobium Tellurium Oxides ANbTeO₆ (A = K, Rb, Cs) with Defect-Pyrochlore Structure

Photoinduced Defect and Surface Chemistry of Niobium Tellurium Oxides ANbTeO₆ (A = K, Rb, Cs) with Defect-Pyrochlore Structure

Synthesis of “Naked” TeO₂Nanoparticles for Biomedical Applications

Coral-Like TeO₂ Microwires for Rechargeable Aluminum Batteries