• Title/Summary/Keyword: Bismuth(Ⅲ) nitrate pentahydrate

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Catalytic Activity of BiVO4-graphene Nanocomposites for the Reduction of Nitrophenols and the Photocatalytic Degradation of Organic Dyes

  • Li, Jiulong;Ko, Jeong Won;Ko, Weon Bae
    • Elastomers and Composites
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    • v.51 no.3
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    • pp.240-249
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    • 2016
  • $BiVO_4$ nanomaterial was synthesized from bismuth (III) nitrate pentahydrate [$Bi(NO_3)_3{\cdot}5H_2O$] and ammonium vanadate (V) [$NH_4VO_3$]. The $BiVO_4$-graphene nanocomposite was fabricated by calcining the $BiVO_4$ nanomaterial and graphene under an oxygen-free atmosphere at $700^{\circ}C$. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to characterize structural and morphological properties of samples. The catalytic activity of the $BiVO_4$-graphene nanocomposite was studied for the reduction of 4-nitrophenol, 3-nitrophenol and 2-nitrophenol by sodium borohydride [$NaBH_4$]. The photocatalytic activity of the $BiVO_4$-graphene nanocomposite was demonstrated by the degradation of organic dyes like BG, MB, MO and RhB under irradiation at 365 nm. The catalytic and photocatalytic activity were studied by UV-vis spectrophotometry.

Synthesis of Pt-Bi/Carbon Electrodes by Reduction Method for Direct Methanol Fuel Cell (환원법에 의한 직접 메탄올 연료전지(DMFC)용 Pt-Bi/Carbon 전극제조)

  • Kim, Kwan Sung;Kim, Min Kyung;Noh, Dong Kyun;Tak, Yongsug;Baeck, Sung-Hyeon
    • Applied Chemistry for Engineering
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    • v.22 no.5
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    • pp.479-485
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    • 2011
  • Pt-Bi/C catalysts supported on carbon black with various Pt/Bi ratios were synthesized by a reduction method. Chloroplatinic acid hydrate ($H_2PtCl_6{\cdot}xH_2O$) and bismuth (III) nitrate pentahydrate ($Bi(NO_3)_3{\cdot}5H_2O$) were used as precursors for Pt and Bi, respectively. Before loading metal on carbon, heat treatment and pretreatment of carbon black in an acidic solution was conducted to enhance the degree of dispersion. The physical property of the synthesized catalysts was investigated by X-ray diffraction and X-ray photoelectron spectroscopy. The XRD pattern of untreated Pt-Bi/C catalyst showed BiPt and $Bi_2Pt$ peaks in addition to Pt peaks. These results imply that Bi atoms were incorporated into the Pt crystal lattice by Pt-Bi alloy formation. The catalytic activity for methanol oxidation was measured using cyclic voltammetry in a mixture of 0.5 M $H_2SO_4$ and 0.5 M $CH_3OH$ aqueous solution. The addition of proper amount of Bi was found to significantly improve catalytic activity for methanol oxidation. The catalytic activity for methanol oxidation was closely related to the stability between electrode and electrolyte. In order to investigate the stability of catalysts, chronoamperometry analysis was carried out in the same solution at 0.6 V.