• Title/Summary/Keyword: $Ag_2Se-graphene$

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Detection of Oxygen Species Generated from Ag2Se-Graphene Heterojunction Photocatalysts with Excellent Visible Light Driven Photocatalytic Performance

  • Meng, Ze-Da;Oh, Won-Chun
    • Korean Journal of Materials Research
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    • v.27 no.5
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    • pp.255-262
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    • 2017
  • Reactive oxygen species (ROS) can be produced by interactions between sunlight and light-absorbing substances in natural water environments and can completely destroy various organic pollutants in waste water. In this study, we used graphene oxide modified $Ag_2Se$ nanoparticles to enhance photochemically generated oxygen (PGO) species activity. Surface area and pore volumes of the $Ag_2Se-graphene$ ($Ag_2Se-G$) samples showed catastrophic decrease due to deposition of $Ag_2Se$. The generation of reactive oxygen species was detected through the oxidation reaction of DPCI to DPCO. The photocurrent density and the PGO effect increase in the case of the use of modified graphene. The PGO effect of the graphene modified with $Ag_2Se$ composites increased significantly due to a synergetic effect between graphene and the $Ag_2Se$ nanoparticles. The photocatalytic activity of sample was evaluated by measuring the degradation of organic pollutants such as methylene blue (MB) and industrial dyes such as Texbrite BA-L (TBA) under visible light.

Ag2Se-Graphene/TiO2 Nanocomposites, Sonochemical Synthesis and Enhanced Photocatalytic Properties Under Visible Light

  • Meng, Ze-Da;Zhu, Lei;Ghosh, Trisha;Park, Chong-Yeon;Ullah, Kefayat;Nikam, Vikram;Oh, Won-Chun
    • Bulletin of the Korean Chemical Society
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    • v.33 no.11
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    • pp.3761-3766
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    • 2012
  • $Ag_2Se$-Graphene/$TiO_2$ composite was synthesized by a facile sonochemical method. The as-prepared products were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis, transmission electron microscopy (TEM) and UV-vis diffuse reflectance spectrophotometer. During the reaction, both of the reduction of graphene oxide and loading of $Ag_2Se$ and $TiO_2$ particles were achieved. The as-prepared $Ag_2Se$-Graphene/$TiO_2$ composites possessed great adsorptivity of dyes, extended light absorption range, and efficient charge separation properties simultaneously. Hence, in the photodegradation of rhodamine B (Rh.B), a significant enhancement in the reaction rate was observed with $Ag_2Se$-Graphene/$TiO_2$ composites, compared to the pure $TiO_2$. The high activity can be attributed to the synergetic effects of high charge mobility, and red shift in absorption edge of $Ag_2Se$-Graphene/$TiO_2$ composites.

Preparation of Ag2Se-Graphene-TiO2 Nanocomposite and its Photocatalytic Degradation (Rh B)

  • Ali, Asghar;Oh, Won-Chun
    • Journal of the Korean Ceramic Society
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    • v.54 no.5
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    • pp.388-394
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    • 2017
  • Here, utilizing rhodamine B (RhB) as standard color dye, we examined the photo degradation proficiency of $Ag_2Se-Graphene-TiO_2$ nanocomposites under visible light irradiation; samples were prepared by ultrasonication techniques and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopic investigation and UV-Vis absorbance spectra examination. Our outcomes demonstrate that the $Ag_2Se-G-TiO_2$ nanocomposite showed significant photodegradation efficiency as compared with those of $TiO_2-G$ and $Ag_2Se-G$, with around 85.2% of Rhodamine B (RhB) degraded after 180 min. It is concluded that the $Ag_2Se-G-TiO_2$ nanocomposite is a competent candidate for dye pollutants.