Antibacterial and photocatalytic activities of controllable (anatase/rutile) mixed phase TiO<sub>2</sub> nanophotocatalysts synthesized <i>via</i> a microwave-assisted sol–gel method

Almashhori, Karima; Ali, Tarek T.; Saeed, Abdu; Al-Wafi, Reem; Aly, Magda M.; Al-Hazmi, Faten

doi:10.1039/c9nj03258d

Cited by 46 publications

(19 citation statements)

References 45 publications

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“…The XRD patterns of anatase and rutile phases of TiO 2 are matched with JCPDS nos. 021-1272 and 021-1276, respectively . The crystalline reflection of ZnBi 2 O 4 is attributed to the tetragonal structure and is matched with JCPDS no.…”

Section: Resultssupporting

confidence: 69%

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Novel p–n Heterojunction Nanocomposite: TiO₂ QDs/ZnBi₂O₄ Photocatalyst with Considerably Enhanced Photocatalytic Activity under Visible-Light Irradiation

Nguyen

Mousavi

et al. 2020

J. Phys. Chem. C

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The practical and widespread application of photocatalysts is limited by the problem of visible-light absorption, the immediate recombination of photogenerated electron–hole pairs, and the low number of active sites on their surface. We synthesized a series of novel TiO2 QDs/ZnBi2O4 nanocomposites through the hydrothermal method to overcome these problems. The formation of nanocomposites and their features were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, photocurrent, field-emission scanning electron microscopy, transmission electron microscopy, electrochemical impedance spectroscopy, photoluminescence, Brunauer–Emmett–Teller, ultraviolet–visible diffuse reflection spectroscopy, and total organic carbon techniques. Among the different ratios of nanocomposites, the TiO2 QDs/ZnBi2O4 (10%) displayed the highest photocatalytic activity under visible-light irradiation, and the corresponding rhodamine B (RhB) degradation rate constant was 1022 × 10–4 min–1, which was nearly 77 and 5.9 times that of the TiO2 and TiO2 QD samples, respectively. In light of the mechanism study, the photocatalytic activity improvement can be ascribed to the p–n heterojunction formation, which led to an increase in the visible-light absorption, suppression of electron–hole recombination, and promotion of charge-carrier transfer. h+, •O2 –, and •OH were also identified as active species responsible for RhB photodegradation through the scavenging test. Phenol, Congo red, malachite green, and methyl orange were also degraded as various pollutants to ensure the prepared nanocomposites’ potential for practical applications. The nanocomposite stability was assessed during reuse evaluation experiments and showed good stability after four consecutive cycles. This work proposes a novel nanocomposite and provides an overview of its features for future applications.

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Section: Resultssupporting

confidence: 69%

“…18 The diffraction peaks corresponding to the (101), ( 004), ( 200), ( 105), ( 211), ( 204), ( 116), (220), and (215) planes of the anatase phase appear at 25. 19 The crystalline reflection of ZnBi 2 O 4 is attributed to the tetragonal structure and is matched with JCPDS no. 043-0449.…”

Section: Resultssupporting

confidence: 69%

Novel p–n Heterojunction Nanocomposite: TiO₂ QDs/ZnBi₂O₄ Photocatalyst with Considerably Enhanced Photocatalytic Activity under Visible-Light Irradiation

Nguyen

Mousavi

et al. 2020

J. Phys. Chem. C

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“…89-4921) and rutile (R, JCPDS No. 89-6975) phases (Challagulla et al 2017;Almashhori et al 2020). The diffraction peaks at 2θ values of 25.4º, 48.1º, 69.1º and 75.3º are allocated to the reflections of the ( 101), ( 200), ( 116) and ( 215) crystal planes of A TiO 2 phase, whereas the crystal planes ( 110), ( 101), ( 111), ( 210), (211) ( 220) and (310) of = r × 100∕I the R TiO 2 phase appears at 27.1º, 36.1º 41.4º, 44.1º, 54.5º, 56.6º and 64.0º, respectively.…”

Section: Depiction Of Gd 2 O 3 -Tio 2 Nanocompositesmentioning

confidence: 99%

“…Figure 2A reveals the structural information of the Gd 2 O 3 -TiO 2 nanocomposites from Raman spectra. The Raman spectra of all photocatalysts consists of the lines of anatase at E g at 145 and 197 cm −1 , B 1g at 398 cm −1 and A 1g at 514 cm −1 (Challagulla et al 2017;Almashhori et al 2020;Ohsaka et al 1978) whereas the line at 447 cm −1 is due to rutile phase. It can be noticed some decrease of the A ( 101) R ( 110)…”

Section: Depiction Of Gd 2 O 3 -Tio 2 Nanocompositesmentioning

confidence: 99%

Photocatalytic visible-light-driven removal of the herbicide imazapyer using nanocomposites based on mesoporous TiO2 modified with Gd2O3

et al. 2020

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In this work, mesoporous Gd 2 O 3 -TiO 2 nanocomposites synthetized by a sol-gel with vary Gd 2 O 3 concentration were investigated for photo-destruction of imazapyr herbicide waste. Textural, structural and surface properties of the synthetized nanocomposites are verified by N 2 physisorption, X-ray diffractometry, HRTEM and various spectroscopic techniques (FTIR, DRS UV-Vis, Raman, PL and XPS). HRTEM micrographs of the calcined Gd 2 O 3 -TiO 2 revealed the existence of a mesoporous matrix consisting of homogeneously distributed TiO 2 nanoparticles (NPs, 12 nm) which are decorated with Ga 2 O 3 nanoparticles. It was found a reverse correlation between the amount of Gd 2 O 3 concentration and the TiO 2 nanoparticle size: the formation of smaller TiO 2 nanoparticles was favored by the use of high Gd 2 O 3 concentration. The photocatalytic efficiency of the synthetized Gd 2 O 3 -TiO 2 nanocomposites was appraised in the photo-destruction of imazapyr herbicide below visible-light irradiation. The best herbicide destruction was achieved using 3%Gd 2 O 3 -TiO 2 photocatalyst and degraded the imazapyr herbicide 20.5 and 8.2 times faster than a commercial P25 and non-promoted TiO 2 , respectively, indicating that modification of TiO 2 with Gd 2 O 3 led to a significant improvement of photocatalyst efficiency. This was explained as due to a lessening of the apparent optical bandgap and the formation of a large amount of surface defect states favoring the separation between electrons and holes. Besides its high efficiency, the 3%Gd 2 O 3 -TiO 2 photocatalyst demonstrated to be recyclable and stable in the visible-light-driven photocatalytic destruction of imazapyr herbicide.

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“…Titania (TiO 2 ) is one of the most significant functional materials available, and it has been widely investigated for hydrogen production, carbon dioxide conversion, energy storage, antimicrobial coatings, and remediation of persistent organic pollutants. , To realize the optimum effectiveness of TiO 2 nanoparticles, various characteristics, such as anatase/rutile phase content, microstructure, morphology, tropology, crystallinity, and surface area, are tuned during the synthesis . The anatase and rutile phases of TiO 2 have been generally studied, due to their outstanding electronic, chemical, physical, and mechanical characteristics .…”

Section: Introductionmentioning

confidence: 99%

New Insights into Crystal Defects, Oxygen Vacancies, and Phase Transition of Ir-TiO₂

et al. 2021

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The impact of iridium (Ir) doping on the oxygen vacancies, relative stability, crystallite size, surface area, and anatase-to-rutile transition of TiO 2 was comprehensively investigated in this study. Ir-doped TiO 2 (Ir-TiO 2 ) was synthesized through a sol−gel technique, and the samples were annealed in the temperature range of 400−700 °C. Density functional theory calculations showed that the energy cost of an oxygen vacancy formation for Ir-TiO 2 was lower, as compared to that of the pristine TiO 2 , with the formation of Ir 3+ states in the band gap. Ir could provide more rutile nucleation sites and accelerate the rutile formation through the crystal strain relaxation. The entropy of mixing was reduced by the incorporation of Ir, which could induce the rutile formation with an increase in Gibbs free energy at temperatures below the normal phase transition temperature for pure TiO 2 . The rutile formation of Ir-TiO 2 could take place at a low annealing temperature (400 °C) compared to pristine TiO 2 (600 °C), indicating that the activation energy for phase transition could be decreased by incorporating Ir. XPS revealed the spin−orbit coupling of Ir 4f peaks, Ir 4f 7/2 (61.96 eV) and Ir 4f 5/2 (64.77 eV), due to the presence of Ir 3+ . Raman studies indicated the formation of charge-compensating oxygen vacancies and the presence of d states by Ir doping. It is concluded that the defects originated because the incorporation of Ir could facilitate rutile nucleation sites and thereby accelerate the phase transition through strain relaxation.

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Antibacterial and photocatalytic activities of controllable (anatase/rutile) mixed phase TiO₂ nanophotocatalysts synthesized via a microwave-assisted sol–gel method

Abstract: TiO2 with different ratios of anatase/rutile phases were synthesized via a microwave assisted sol–gel method and by applying a single source precursor (SSP) with a constant concentration of nitric acid that was used as the structure directing agent.

Cited by 46 publications

References 45 publications

Novel p–n Heterojunction Nanocomposite: TiO₂ QDs/ZnBi₂O₄ Photocatalyst with Considerably Enhanced Photocatalytic Activity under Visible-Light Irradiation

Novel p–n Heterojunction Nanocomposite: TiO₂ QDs/ZnBi₂O₄ Photocatalyst with Considerably Enhanced Photocatalytic Activity under Visible-Light Irradiation

Photocatalytic visible-light-driven removal of the herbicide imazapyer using nanocomposites based on mesoporous TiO2 modified with Gd2O3

New Insights into Crystal Defects, Oxygen Vacancies, and Phase Transition of Ir-TiO₂

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Antibacterial and photocatalytic activities of controllable (anatase/rutile) mixed phase TiO2 nanophotocatalysts synthesized via a microwave-assisted sol–gel method

Abstract: TiO2 with different ratios of anatase/rutile phases were synthesized via a microwave assisted sol–gel method and by applying a single source precursor (SSP) with a constant concentration of nitric acid that was used as the structure directing agent.

Cited by 46 publications

References 45 publications

Novel p–n Heterojunction Nanocomposite: TiO2 QDs/ZnBi2O4 Photocatalyst with Considerably Enhanced Photocatalytic Activity under Visible-Light Irradiation

Novel p–n Heterojunction Nanocomposite: TiO2 QDs/ZnBi2O4 Photocatalyst with Considerably Enhanced Photocatalytic Activity under Visible-Light Irradiation

Photocatalytic visible-light-driven removal of the herbicide imazapyer using nanocomposites based on mesoporous TiO2 modified with Gd2O3

New Insights into Crystal Defects, Oxygen Vacancies, and Phase Transition of Ir-TiO2

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Product

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Antibacterial and photocatalytic activities of controllable (anatase/rutile) mixed phase TiO₂ nanophotocatalysts synthesized via a microwave-assisted sol–gel method

Novel p–n Heterojunction Nanocomposite: TiO₂ QDs/ZnBi₂O₄ Photocatalyst with Considerably Enhanced Photocatalytic Activity under Visible-Light Irradiation

Novel p–n Heterojunction Nanocomposite: TiO₂ QDs/ZnBi₂O₄ Photocatalyst with Considerably Enhanced Photocatalytic Activity under Visible-Light Irradiation

New Insights into Crystal Defects, Oxygen Vacancies, and Phase Transition of Ir-TiO₂