Enhancement in the photocatalytic activity of Bi2Ti2O7 nanopowders synthesised via Pechini vs Co-Precipitation method

Kumar, Vishesh; Sharma, Rishabh; Kumar, Sushil; Kaur, Manpreet; Sharma, Jagmohan

doi:10.1016/j.ceramint.2019.07.015

Cited by 28 publications

(17 citation statements)

References 48 publications

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“…Meanwhile, a deviation exists in the literature regarding the specific surface area of the bismuth titanate pyrochlore (5.75−16.38 m 2 /g), which is caused by different annealing parameters, as well as additional processing steps (hydrothermal treatment) during coprecipitation synthesis. 32,33,38,43 Electronic Properties and Optical Absorption Spectra. The well-optimized crystal structures of BTO models were utilized for further analysis of the electronic structure and optical properties.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Photocatalytic Properties of Bi_2–xTi₂O_7–1.5x (x = 0, 0.5) Pyrochlores: Hybrid DFT Calculations and Experimental Study

et al. 2020

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The photocatalytic properties of Bi2–x Ti2O7–1.5x (x = 0, 0.5) pyrochlores are examined via ab initio calculations and experiments. A coprecipitation method is applied for the synthesis of nanopowder pyrochlores. The pyrochlore phase formation starts at 500 °C (Bi2Ti2O7) and 550 °C (Bi1.5Ti2O6.25). Nanopowders are found to be a metastable character of pyrochlore phases. The presence of bismuth and oxygen vacancies enhances the thermal stability of the Bi1.5Ti2O6.25 phase in comparison with the Bi2Ti2O7 phase. The estimated crystallite size is 30–40 nm with noticeable agglomerates of about 100–300 nm according to scanning electron microscopy (SEM) and with the formation of particles (510–580 nm) in the aqueous medium. The isoelectric points of the nanopowders seem to be shifted to the strongly acidic region, resulting in the formation of negative surface particle charges of −33 mV (Bi2Ti2O7) and −27 mV (Bi1.5Ti2O6.25) at pH 5.88 in distilled water. The specific surface area is 11.5 m2/g (Bi2Ti2O7) and 12.00 m2/g (Bi1.5Ti2O6.25). The use of the generalized gradient approximation (GGA) with the Perdew–Burke–Ernzerhof (PBE) functional allows achieving an excellent agreement between theoretical and experimental structural parameters. The screened Coulomb hybrid HSE03 functional is the most appropriate for describing the optoelectronic properties. Bismuth titanate pyrochlores are wide-gap semiconductors with strong abilities to be active photocatalysts under visible irradiation. The optical E g values for direct/indirect transition according to the experiment, 3.19/2.94 eV (x = 0) and 3.24/3.03 eV (x = 0.5), and the DFT/HSE03 calculations, 2.92/2.87 (x = 0) and 3.42/– eV (x = 0.5), are in the visible light region and are close. The calculated low effective masses of the charge carriers and suitable band edge positions confirm the ability of the pyrochlores to act as photocatalysts. The photocatalytic activity has been evaluated through the decomposition of rhodamine B under visible irradiation. Bi2Ti2O7 shows the highest activity in comparison with Bi1.5Ti2O6.25, which is in good agreement with theoretically predicted and experimentally revealed characteristics.

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Section: ■ Results and Discussionmentioning

confidence: 99%

Photocatalytic Properties of Bi_2–xTi₂O_7–1.5x (x = 0, 0.5) Pyrochlores: Hybrid DFT Calculations and Experimental Study

et al. 2020

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“…This is probably caused by the increase of the coverage of the La2Sn2O7 surface by the highly dispersed CuO until the monolayer dispersion capacity is reached. Moreover, these results also indicate that there is a strong interaction between the sub-monolayer/monolayer CuO and the La2Sn2O7 support [54,55]. In contrast, when the CuO content was higher than the monolayer dispersion capacity (i.e., > 4.3%), the positions of the three typical Raman peaks of La2Sn2O7 remained nearly constant, indicating that the excess CuO was located over the initially formed CuO monolayer as microsized crystallites, thus having a much weaker interaction with the support.…”

Section: Raman Spectroscopy Measurementsmentioning

confidence: 60%

Stable CuO/La2Sn2O7 catalysts for soot combustion: Study on the monolayer dispersion behavior of CuO over a La2Sn2O7 pyrochlore support

Feng

et al. 2021

Chinese Journal of Catalysis

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“…Figura 2: Representação esquemática do processo Pechin i Fonte: Kumar et al, 2019 Entretanto, mesmo se tratando de um método bastante promissor, esta rota é pouco reproduzida e discutida para a síntese de HAp. A seguir é apresentado todos os artigos resultantes da busca relacionada a produção de hidroxiapatita através do método dos percursores poliméricos.…”

Section: Método Pechiniunclassified

Síntese De Hidroxiapatita via Rota Pechini: Uma Breve Revisão

Almeida¹,

Costa²,

Farias³

et al. 2022

Análise E Desenvolvimento De Materiais Cerâmicos: Novas Perspectivas

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Enhancement in the photocatalytic activity of Bi2Ti2O7 nanopowders synthesised via Pechini vs Co-Precipitation method

Cited by 28 publications

References 48 publications

Photocatalytic Properties of Bi_2–xTi₂O_7–1.5x (x = 0, 0.5) Pyrochlores: Hybrid DFT Calculations and Experimental Study

Photocatalytic Properties of Bi_2–xTi₂O_7–1.5x (x = 0, 0.5) Pyrochlores: Hybrid DFT Calculations and Experimental Study

Stable CuO/La2Sn2O7 catalysts for soot combustion: Study on the monolayer dispersion behavior of CuO over a La2Sn2O7 pyrochlore support

Síntese De Hidroxiapatita via Rota Pechini: Uma Breve Revisão

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Enhancement in the photocatalytic activity of Bi2Ti2O7 nanopowders synthesised via Pechini vs Co-Precipitation method

Cited by 28 publications

References 48 publications

Photocatalytic Properties of Bi2–xTi2O7–1.5x (x = 0, 0.5) Pyrochlores: Hybrid DFT Calculations and Experimental Study

Photocatalytic Properties of Bi2–xTi2O7–1.5x (x = 0, 0.5) Pyrochlores: Hybrid DFT Calculations and Experimental Study

Stable CuO/La2Sn2O7 catalysts for soot combustion: Study on the monolayer dispersion behavior of CuO over a La2Sn2O7 pyrochlore support

Síntese De Hidroxiapatita via Rota Pechini: Uma Breve Revisão

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Photocatalytic Properties of Bi_2–xTi₂O_7–1.5x (x = 0, 0.5) Pyrochlores: Hybrid DFT Calculations and Experimental Study

Photocatalytic Properties of Bi_2–xTi₂O_7–1.5x (x = 0, 0.5) Pyrochlores: Hybrid DFT Calculations and Experimental Study