Band gap narrowing of titanium dioxide (TiO2) nanocrystals by electrochemically active biofilms and their visible light activity

Kalathil, Shafeer; Khan, Mohammad Mansoob; Lee, Jintae

doi:10.1039/c3nr01280h

Cited by 159 publications

(162 citation statements)

References 26 publications

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“…[55][56][57] Among the values of ∆ H-L , the PBEx results are analogous with the experimental band gap of bulk anatase (3.20 eV [58][59][60] ) and the TiO 2 NP (mixture of rutile and anatase phase; ca. 3.10 eV [61][62][63] ).…”

Section: Resultsmentioning

confidence: 99%

Single oxygen vacancies of (TiO₂)₃₅as a prototype reduced nanoparticle: implication for photocatalytic activity

Kim

Lee

et al. 2016

Phys. Chem. Chem. Phys.

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Titanium dioxide (TiO2), as a semiconductor metal oxide, has been one of the most popular materials studied in the field of photocatalysis. In the present study, the properties of single oxygen vacancies of (TiO2)35, a prototype of anatase nanoparticle, were investigated by DFT calculations. (TiO2)35 is the minimum sized model (~ 2 nm) as bipyramidal nanoparticle with anatase phase and eight {101} facets. All the available oxygen vacancies at various sites according to position, coordination number, and distance from the center atom were examined. The geometric, energetic and electronic properties of the reduced TiO2 clusters were analyzed by hybrid DFT functionals with different Hartree-Fock exchange ratio (0, 12.5 and 25 %). It was found that the structure of pristine (TiO2)35 is somewhat different from bulk lattice with relatively high surface to volume ratio. Moreover, the particular high (three)-coordinated oxygen atom is energetically most favorable for oxygen vacancy formation from nanoparticle mainly due to substantially high relaxation energy. TiO2 nanoparticle has low oxygen vacancy formation energy and narrow band gap by defect state, and can be utilized as an efficient photocatalyst material.

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Section: Resultsmentioning

confidence: 99%

Single oxygen vacancies of (TiO₂)₃₅as a prototype reduced nanoparticle: implication for photocatalytic activity

Kim

Lee

et al. 2016

Phys. Chem. Chem. Phys.

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“…Photocatalysis is an alternative since it allows their rapid and efficient removal from water, transforming them into by-products with lower toxicity [5,6]. Among several semiconductor materials, titanium dioxide (TiO 2 ) has a band gap of ~3.10 eV [8,9], which make it a suitable photocatalyst for the degradation of organic pollutants because of its low cost, unique optical properties, and availability [10].…”

Section: Introductionmentioning

confidence: 99%

Orthogonal experimental design of titanium dioxide—Poly(methyl methacrylate) electrospun nanocomposite membranes for photocatalytic applications

Vild

Teixeira

Kühn

et al. 2016

Journal of Environmental Chemical Engineering

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“…However, the band gap energy variations seen could be caused by defects, crystal structure, and temperature of MO nanoparticles. 41,42 Photoexcitation responses can also be confirmed using UV and Fourier transforminfrared spectroscopy (FT-IR). 43 The dual UV-MO nanoparticle hybrid system can be applied for the disinfection of bacteria and viruses.…”

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confidence: 99%

Dual UV irradiation-based metal oxide nanoparticles for enhanced antimicrobial activity in <em>Escherichia coli</em> and M13 bacteriophage

Jin¹,

Hwang²,

Lee³

et al. 2017

IJN

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Metal oxide (MO) nanoparticles have been studied as nano-antibiotics due to their antimicrobial activities even in antibiotic-resistant microorganisms. We hypothesized that a hybrid system of dual UV irradiation and MO nanoparticles would have enhanced antimicrobial activities compared with UV or MO nanoparticles alone. In this study, nanoparticles of ZnO, ZnTiO 3 , MgO, and CuO were selected as model nanoparticles. A dual UV collimated beam device of UV-A and UV-C was developed depending upon the lamp divided by coating. Physicochemical properties of MO nanoparticles were determined using powder X-ray diffractometry (PXRD), Brunauer-Emmett-Teller analysis, and field emission-scanning electron microscopy with energy-dispersive X-ray spectroscopy. Atomic force microscopy with an electrostatic force microscopy mode was used to confirm the surface topology and electrostatic characteristics after dual UV irradiation. For antimicrobial activity test, MO nanoparticles under dual UV irradiation were applied to Escherichia coli and M13 bacteriophage (phage). The UV-A and UV-C showed differential intensities in the coated and uncoated areas (UV-A, coated = uncoated; UV-C, coated ≪ uncoated). MO nanoparticles showed sharp peaks in PXRD patterns, matched to pure materials. Their primary particle sizes were less than 100 nm with irregular shapes, which had an 8.6~25.6 m 2 /g of specific surface area with mesopores of 22~262 nm. The electrostatic properties of MO nanoparticles were modulated after UV irradiation. ZnO, MgO, and CuO nanoparticles, except ZnTiO 3 nanoparticles, showed antibacterial effects on E. coli . Antimicrobial effects on E. coli and phages were also enhanced after cyclic exposure of dual UV and MO nanoparticle treatment using the uncoated area, except ZnO nanoparticles. Our results demonstrate that dual UV-MO nanoparticle hybrid system has a potential for disinfection. We anticipate that it can be developed as a next-generation disinfection system in pharmaceutical industries and water purification systems.

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Band gap narrowing of titanium dioxide (TiO2) nanocrystals by electrochemically active biofilms and their visible light activity

Cited by 159 publications

References 26 publications

Single oxygen vacancies of (TiO₂)₃₅as a prototype reduced nanoparticle: implication for photocatalytic activity

Single oxygen vacancies of (TiO₂)₃₅as a prototype reduced nanoparticle: implication for photocatalytic activity

Orthogonal experimental design of titanium dioxide—Poly(methyl methacrylate) electrospun nanocomposite membranes for photocatalytic applications

Dual UV irradiation-based metal oxide nanoparticles for enhanced antimicrobial activity in <em>Escherichia coli</em> and M13 bacteriophage

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Band gap narrowing of titanium dioxide (TiO2) nanocrystals by electrochemically active biofilms and their visible light activity

Cited by 159 publications

References 26 publications

Single oxygen vacancies of (TiO2)35as a prototype reduced nanoparticle: implication for photocatalytic activity

Single oxygen vacancies of (TiO2)35as a prototype reduced nanoparticle: implication for photocatalytic activity

Orthogonal experimental design of titanium dioxide—Poly(methyl methacrylate) electrospun nanocomposite membranes for photocatalytic applications

Dual UV irradiation-based metal oxide nanoparticles for enhanced antimicrobial activity in <em>Escherichia coli</em> and M13 bacteriophage

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Single oxygen vacancies of (TiO₂)₃₅as a prototype reduced nanoparticle: implication for photocatalytic activity

Single oxygen vacancies of (TiO₂)₃₅as a prototype reduced nanoparticle: implication for photocatalytic activity