Photocatalytic Hydrogenation on Semiconductor Particles

Kohtani, Shigeru; Yoshioka, Eito; Miyabe, Hideto

doi:10.5772/45732

Cited by 18 publications

(20 citation statements)

References 83 publications

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“…The measured values of the band gap for anatase and P25 anatase + rutile particles were 2.85 and 3.22 eV, respectively (the absorption spectra and Tauc plots are given in Figure S4 in the Supporting Information). The measured band gap for P25 anatase + rutile is in a good agreement with the reference one of the anatase phase, which is 3.2 eV . On the other hand, the measured band gap for anatase particles is different, which might be due to the fast sedimentation of the particles affecting the data acquisition.…”

Section: Resultssupporting

confidence: 75%

“…The measured band gap for P25 anatase + rutile is in a good agreement with the reference one of the anatase phase, which is 3.2 eV. 33 On the other hand, the measured band gap for anatase particles is different, which might be due to the fast sedimentation of the particles affecting the data acquisition. Nevertheless, the irradiation with a 367 nm UV lamp (corresponding to 3.38 eV photon energy) should result in the effective generation of electron−hole pairs in both types of nanoparticles.…”

Section: ■ Results and Discussionsupporting

confidence: 67%

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Freezing-Induced Loading of TiO₂ into Porous Vaterite Microparticles: Preparation of CaCO₃/TiO₂ Composites as Templates To Assemble UV-Responsive Microcapsules for Wastewater Treatment

et al. 2020

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The photocatalytic degradation of organic molecules is one of the effective ways for water purification. At this point, photocatalytic microreactor systems seem to be promising to enhance the versatility of the photoassisted degradation approach. Herein, we propose photoresponsive microcapsules prepared via layer-by-layer assembly of polyelectrolytes on the novel CaCO 3 /TiO 2 composite template cores. The preparation of CaCO 3 /TiO 2 composite particles is challenging because of the poor compatibility of TiO 2 and CaCO 3 in an aqueous medium. To prepare stable CaCO 3 / TiO 2 composites, TiO 2 nanoparticles were loaded into mesoporous CaCO 3 microparticles with a freezing-induced loading technique. The inclusion of TiO 2 nanoparticles into CaCO 3 templates was evaluated with scanning electron microscopy and elemental analysis with respect to their type, concentration, and number of loading iterations. Upon polyelectrolyte shell assembly, the CaCO 3 matrix was dissolved, resulting in microreactor capsules loaded with TiO 2 nanoparticles. The photoresponsive properties of the resulted capsules were tested by photoinduced degradation of the low-molecule dye rhodamine B in aqueous solution and fluorescently labeled polymer molecules absorbed on the capsule surface under UV light. The exposure of the capsules to UV light resulted in a pronounced degradation of rhodamine B in capsule microvolume and fluorescent molecules on the capsule surface. Finally, the versatility of preparation of multifunctional photocatalytic and magnetically responsive capsules was demonstrated by iterative freezing-induced loading of TiO 2 and magnetite Fe 3 O 4 nanoparticles into CaCO 3 templates.

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Section: Resultssupporting

confidence: 75%

Section: ■ Results and Discussionsupporting

confidence: 67%

Freezing-Induced Loading of TiO₂ into Porous Vaterite Microparticles: Preparation of CaCO₃/TiO₂ Composites as Templates To Assemble UV-Responsive Microcapsules for Wastewater Treatment

et al. 2020

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“…Recently it was also found that fine platinum nanoparticles in the size range from 1 to 4 nm revealed the highest activity under visible light irradiation for reaction of organic pollutants degradation from aqueous stream [11]. Kohtani et al reported that fine platinum particles loaded on photocatalyst greatly improved the efficiency of hydrogen evolution from water or alcohol under irradiation [22]. Shiraishi et al found that Pt-Cu bimetallic nanoparticles deposited on anatase with particle size from 3 nm to 5 nm exhibited the highest photocatalytic activity [23].…”

Section: Discussionmentioning

confidence: 98%

The effect of nanoparticles size on photocatalytic and antimicrobial properties of Ag-Pt/TiO2 photocatalysts

Zielińska‐Jurek

Wei

Wysocka

et al. 2015

Applied Surface Science

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Please cite this article as: A. Zielińska-Jurek, Z. Wei, I. Wysocka, P. Szweda, E. Kowalska, The effect of nanoparticles size on photocatalytic and antimicrobial properties of Ag-Pt/TiO 2 photocatalysts, Applied Surface Science (2015), http://dx.A c c e p t e d M a n u s c r i p t Highlights  Enhanced photocatalytic activity under visible light for bimetallic Ag-Pt/TiO 2 was observed  Phenol was removed efficiently after 60 min. irradiation under Vis  Most active sample contains fine Pt (1-3nm) on TiO 2  Ag/TiO 2 , Ag-Pt/TiO 2 revealed antimicrobial activity AbstractAg-Pt -modified TiO 2 nanocomposites were synthesized using the sol-gel method.Bimetallic modified TiO 2 nanoparticles exhibited improved photocatalytic activity under visible-light irradiation, better than monometallic Ag/TiO 2 and Pt/TiO 2 nanoparticles (NPs). All modified powders showed localized surface plasmon resonance (LSPR) in visible region. The photocatalysts' characteristics by X-ray diffractometry (XRD), scanning transmission electron microscopy (STEM), diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption (BET method for specific surface area) showed that sample with the highest photocatalytic activity had anatase structure, about 93 m 2 /g specific surface area, maximum plasmon absorption at ca. 420 nm and contained small NPs of silver of 6 nm and very fine platinum NPs of 3 nm.The photocatalytic activity was estimated by measuring the decomposition rate of phenol in 0.2 mM aqueous solution under Vis and UV/Vis light irradiation. It was found that size of platinum was decisive for the photocatalytic activity under visible light irradiation, i.e., the smaller Pt NPs were, the higher was photocatalytic activity. While, antimicrobial activities, estimated for bacteria E. coli and St. aureus, and pathogenic fungi belonging to A c c e p t e d M a n u s c r i p t Candida family, were only observed for photocatalysts containing silver, i.e., Ag/TiO 2 and Ag-Pt/TiO 2 nanocomposites.

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“…Many works on the hydrogen evolution reaction (HER) with semiconductor particles have been conducted, and relatively high efficiency photocatalysts were invented. − However, most of the great works still utilized toxic materials such as Cd-based materials with a precious Pt cocatalyst and a strong hole scavenger such as Na 2 S and Na 2 SO 3 which were not environment-friendly. The other great challenge is the heating from high power of light sources that have been used in those works.…”

Section: Introductionmentioning

confidence: 99%

Concept of Stagnant Capillarity Water in the Nanoporous SiO₂@(Zn,Ni)(O,S) Nanocomposite Photocatalyst as a Strategy to Improve Hydrogen Evolution

Gultom

Abdullah

Kuo

2019

ACS Appl. Mater. Interfaces

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(Zn,Ni)(O,S) nanoparticles were uniformly deposited on nanoporous SiO2 spheres to form SiO2@(Zn,Ni)(O,S) nanocomposites (NCs). To obtain optimum deposition of (Zn,Ni)(O,S) on the SiO2 spheres for the hydrogen evolution reaction (HER), different amounts of 0.25, 0.5, 1, and 1.5 mmol zinc precursor for (Zn,Ni)(O,S) were deposited on SiO2 to obtain different SiO2@(Zn,Ni)(O,S) NCs. All the as-prepared catalysts were examined with X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, electrochemical impedance spectroscopy, photocurrent response, photoluminescence spectral studies. Finally, the HER performance was evaluated with SiO2@(Zn,Ni)(O,S). The best SiO2@(Zn,Ni)(O,S)-0.5 surprisingly reached 41.1 mmol/gh for generating H2, which was about a 840% increase as compared to that of the SiO2 sphere-free one. The great improvement in the HER rate was due to the utilization of nanoporous SiO2 spheres. The concept of stagnant capillarity water, adopted from the leaf vein system, was applied to explain the enhanced HER reaction.

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Photocatalytic Hydrogenation on Semiconductor Particles

Cited by 18 publications

References 83 publications

Freezing-Induced Loading of TiO₂ into Porous Vaterite Microparticles: Preparation of CaCO₃/TiO₂ Composites as Templates To Assemble UV-Responsive Microcapsules for Wastewater Treatment

Freezing-Induced Loading of TiO₂ into Porous Vaterite Microparticles: Preparation of CaCO₃/TiO₂ Composites as Templates To Assemble UV-Responsive Microcapsules for Wastewater Treatment

The effect of nanoparticles size on photocatalytic and antimicrobial properties of Ag-Pt/TiO2 photocatalysts

Concept of Stagnant Capillarity Water in the Nanoporous SiO₂@(Zn,Ni)(O,S) Nanocomposite Photocatalyst as a Strategy to Improve Hydrogen Evolution

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Photocatalytic Hydrogenation on Semiconductor Particles

Cited by 18 publications

References 83 publications

Freezing-Induced Loading of TiO2 into Porous Vaterite Microparticles: Preparation of CaCO3/TiO2 Composites as Templates To Assemble UV-Responsive Microcapsules for Wastewater Treatment

Freezing-Induced Loading of TiO2 into Porous Vaterite Microparticles: Preparation of CaCO3/TiO2 Composites as Templates To Assemble UV-Responsive Microcapsules for Wastewater Treatment

The effect of nanoparticles size on photocatalytic and antimicrobial properties of Ag-Pt/TiO2 photocatalysts

Concept of Stagnant Capillarity Water in the Nanoporous SiO2@(Zn,Ni)(O,S) Nanocomposite Photocatalyst as a Strategy to Improve Hydrogen Evolution

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Product

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Freezing-Induced Loading of TiO₂ into Porous Vaterite Microparticles: Preparation of CaCO₃/TiO₂ Composites as Templates To Assemble UV-Responsive Microcapsules for Wastewater Treatment

Freezing-Induced Loading of TiO₂ into Porous Vaterite Microparticles: Preparation of CaCO₃/TiO₂ Composites as Templates To Assemble UV-Responsive Microcapsules for Wastewater Treatment

Concept of Stagnant Capillarity Water in the Nanoporous SiO₂@(Zn,Ni)(O,S) Nanocomposite Photocatalyst as a Strategy to Improve Hydrogen Evolution