Fabrication of ZnO and TiO2 Nanotubes via Flexible Electro-Spun Nanofibers for Photocatalytic Applications

Web-like architectures of ZnO and TiO2 nanotubes were fabricated based on a three-step process of templating polymer nanofibers produced by electrospinning (step 1). The electrospun polymer nanofibers were covered by radio-frequency magnetron sputtering with thin layers of semiconducting materials (step 2), with FESEM observations proving uniform deposits over their entire surface. ZnO or TiO2 nanotubes were obtained by subsequent calcination (step 3). XRD measurements proved that the nanotubes were of a single crystalline phase (wurtzite for ZnO and anatase for TiO2) and that no other crystalline phases appeared. No other elements were present in the composition of the nanotubes, confirmed by EDX measurements. Reflectance spectra and Tauc plots of Kubelka–Munk functions revealed that the band gaps of the nanotubes were lower than those of the bulk materials (3.05 eV for ZnO and 3.16 eV for TiO2). Photocatalytic performances for the degradation of Rhodamine B showed a large degradation efficiency, even for small quantities of nanotubes (0.5 mg/10 mL dye solution): ~55% for ZnO, and ~95% for TiO2.

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Design and Performance of Novel Self-Cleaning g-C3N4/PMMA/PUR Membranes

Polymers ◽

10.3390/polym12040850 ◽

2020 ◽

Vol 12 (4) ◽

pp. 850 ◽

Cited By ~ 2

Author(s):

Ladislav Svoboda ◽

Nadia Licciardello ◽

Richard Dvorský ◽

Jiří Bednář ◽

Jiří Henych ◽

...

Keyword(s):

Methylene Blue ◽

Thin Layers ◽

Photocatalytic Reaction ◽

Potential Toxicity ◽

Material Loss ◽

Contaminant Control ◽

Biological Contaminant ◽

Self Cleaning ◽

And Performance ◽

Photocatalytic Applications

In the majority of photocatalytic applications, the photocatalyst is dispersed as a suspension of nanoparticles. The suspension provides a higher surface for the photocatalytic reaction in respect to immobilized photocatalysts. However, this implies that recovery of the particles by filtration or centrifugation is needed to collect and regenerate the photocatalyst. This complicates the regeneration process and, at the same time, leads to material loss and potential toxicity. In this work, a new nanofibrous membrane, g-C3N4/PMMA/PUR, was prepared by the fixation of exfoliated g-C3N4 to polyurethane nanofibers using thin layers of poly(methyl methacrylate) (PMMA). The optimal amount of PMMA was determined by measuring the adsorption and photocatalytic properties of g-C3N4/PMMA/PUR membranes (with a different PMMA content) in an aqueous solution of methylene blue. It was found that the prepared membranes were able to effectively adsorb and decompose methylene blue. On top of that, the membranes evinced a self-cleaning behavior, showing no coloration on their surfaces after contact with methylene blue, unlike in the case of unmodified fabric. After further treatment with H2O2, no decrease in photocatalytic activity was observed, indicating that the prepared membrane can also be easily regenerated. This study promises possibilities for the production of photocatalytic membranes and fabrics for both chemical and biological contaminant control.

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Recent advancements on the sustainable biochar based semiconducting materials for photocatalytic applications: A state of the art review

Journal of Cleaner Production ◽

10.1016/j.jclepro.2021.129899 ◽

2021 ◽

pp. 129899

Author(s):

Palagiri Bhavani ◽

Murid Hussain ◽

Young-Kwon Park

Keyword(s):

State Of The Art ◽

Semiconducting Materials ◽

Photocatalytic Applications

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Near-IR transparent conductive amorphous tungsten oxide thin layers by non-reactive radio-frequency magnetron sputtering

EPJ Web of Conferences ◽

10.1051/epjconf/202125505003 ◽

2021 ◽

Vol 255 ◽

pp. 05003

Author(s):

Hao Chen ◽

Alessandro Chiasera ◽

Cristina Armellini ◽

Giorgio Speranza ◽

Stefano Varas ◽

...

Keyword(s):

Electrical Conductivity ◽

Tin Oxide ◽

Indium Tin Oxide ◽

Figure Of Merit ◽

Rf Sputtering ◽

Thin Layers ◽

Radio Frequency Magnetron Sputtering ◽

Amorphous Thin Films ◽

Near Ir ◽

Electric Contacts

Key assets for transparent electric contacts in optoelectronic applications are high conductivity and large transparency over extended spectral range. Indium-Tin-Oxide and Aluminium-doped-Zinc-oxide are commercial examples, with their electrical conductivity resembling those of metals, despite, their transparency being limited up to 1.5µm. This work introduces smooth and compact amorphous thin films of n-type semiconducting WO3-x prepared by RF-sputtering followed by annealing in dry air, as optical layers of tailorable dielectric properties. We evaluate Figure of Merit, combining electrical conductivity and optical transparency, and rate the performances as a transparent conductive layer.

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Thoroughly mesoporous TiO2 nanotubes prepared by a foaming agent-assisted electrospun template for photocatalytic applications

RSC Advances ◽

10.1039/c6ra00241b ◽

2016 ◽

Vol 6 (25) ◽

pp. 21043-21047 ◽

Cited By ~ 7

Author(s):

Y. Lv ◽

Z. L. Xu ◽

H. Asai ◽

N. Shimada ◽

K. Nakane

Keyword(s):

Tio2 Nanotubes ◽

Mesoporous Tio2 ◽

Template Method ◽

Foaming Agent ◽

Photocatalytic Applications

A thoroughly mesoporous long TiO2 nanotube with intact morphology was firstly prepared using a foaming agent-assisted electrospun template method for photocatalytic applications.

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High Resolution X-ray Diffraction for the Characterization of Semiconducting Materials

Advances in X-ray Analysis ◽

10.1154/s0376030800019388 ◽

1989 ◽

Vol 33 ◽

pp. 1-11 ◽

Cited By ~ 8

Author(s):

B. K. Tanner

Keyword(s):

Bragg Peak ◽

Thin Layers ◽

X Ray Diffraction ◽

Semiconducting Materials ◽

Multiple Reflections ◽

X Ray ◽

Analyzer Crystal ◽

Glancing Angle ◽

Heteroepitaxial Layers

AbstractUse of a reference crystal to condition the beam in the double-axis diffractometer permits the Bragg peak width to be reduced to the correlation of the two crystal reflecting ranges. Some recent applications of double axis diffractometry to the study of heteroepitaxial layers are discussed. The advantages of multiple reflections for beam conditioning and the four reflection DuMond monochromator are examined. Glancing incidence and exit diffractometry permits the study of very thin layers, down to a few tens of nanometres in thickness and both synchrotron radiation and skew reflections can be used to tune the glancing angle close to the critical angle. Recent applications of triple-axis diffraction, where an analyzer crystal is used after the specimen, to the study of very thin single epitaxial layers and multiquantum well structures are reviewed.

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Independent Determination of the Thermal Diffusivity and Conductivity of a Thin Metallic Layer Deposited on Silica

ASME 2008 First International Conference on Micro/Nanoscale Heat Transfer, Parts A and B ◽

10.1115/mnht2008-52299 ◽

2008 ◽

Author(s):

Christian Fretigny ◽

Jean Paul Roger ◽

Li Liu ◽

Danie`le Fournier

Keyword(s):

Thermal Diffusivity ◽

Careful Analysis ◽

Thin Layers ◽

Heat Diffusion ◽

Bulk Materials ◽

Thermal Insulator ◽

Independent Determination ◽

Lateral Temperature ◽

Lateral Heat

It is well known that the thermal parameters of materials confined in thin layers may significantly differ from their bulk value. Lateral heat diffusion thermoreflectance experiment is a very powerful tool for determining directly the thermal diffusivity of bulk materials and of layered structure. Nevertheless, in the latter case, experimental data are fitted with the help of a heat diffusion model in which the layer thermal conductivity and thermal diffusivity are taken together into consideration. In this paper, we show that both parameters can be determined independently, in the case of a thermal conductive layer deposited on a thermal insulator, with a careful analysis of the amplitude and the phase of the lateral temperature field associated to a point source.

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Evaluation of several commercial polymers as support for TiO2 in photocatalytic applications

Global NEST Journal ◽

10.30955/gnj.001446 ◽

2014 ◽

Vol 16 (3) ◽

pp. 525-535 ◽

Cited By ~ 2

Keyword(s):

Methyl Methacrylate ◽

Photocatalytic Oxidation ◽

Sol Gel ◽

Synthetic Polymers ◽

Poly Methyl Methacrylate ◽

Calcination Step ◽

Optical And Mechanical Properties ◽

Commercial Polymers ◽

Processing Techniques ◽

Photocatalytic Applications

This work is aimed to select the best synthetic polymers available in the market with high transmittance in the TiO2 activation range that can be coated with the semiconductor and withstand the photocatalytic oxidation conditions. <div> Among eleven commercial organic polymers with different additives and processing techniques, only polypropylene, polystyrene, sheet moulding processed poly (methyl methacrylate) and rigid polyvinyl chloride presented transmittances higher than 80% at 360 nm , which allows irradiation there through. The selected polymers were coated without a calcination step with anatase-TiO2 obtained by sol-gel. Their weathering was studied during 150 days of exposure to solar radiation, with and without the TiO2 layer. It was observed that only poly (methyl methacrylate) retains the titania and the good optical and mechanical properties after the natural weathering, and thus is the best candidate for immobilization of TiO2 for air photocatalytic treatment applications. </div>

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