کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
583286 1453170 2008 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Photocatalytic removal of M2+ (Ni2+, Cu2+, Zn2+, Cd2+, Hg2+ and Ag+) over new catalyst CuCrO2
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی بهداشت و امنیت شیمی
پیش نمایش صفحه اول مقاله
Photocatalytic removal of M2+ (Ni2+, Cu2+, Zn2+, Cd2+, Hg2+ and Ag+) over new catalyst CuCrO2
چکیده انگلیسی
The metal ions M2+ (Ni2+, Cu2+, Zn2+, Cd2+, Hg2+ and Ag+) are potentially toxic. Their electro deposition has been carried out in aqueous air-equilibrated CuCrO2 suspension upon visible illumination. The delafossite CuCrO2 is p-type semiconductor characterized by a low band gap (1.28 eV) and a long-term chemical stability. The corrosion rate is found to be 10−2 μmol m−2 month−1 in aqua regia. The oxide has been elaborated through nitrate route where the specific surface area is increased via the surface/bulk ratio. A correlation exists between the dark M2+ adsorption, the redox potential of M2+/0 couple and the conduction band of CuCrO2 positioned at −1.06 VSCE. Ag+ cannot be photoreduced because of its positive potential located far above the valence band. By contrast, Zn2+ is efficiently deposited due to the large driving force at the interface. The improved photoactivity of copper with a deposition percentage (90%) is attributed to the strong dark adsorption onto the surface catalyst. The results indicate a competitive effect with the water reduction; it has been observed that the M2+ deposition goes parallel with the hydrogen evolution. Such behavior is attributed to the low H2 over voltage when ultra fine aggregate of M islands are photodeposited onto CuCrO2 substrate.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Hazardous Materials - Volume 158, Issues 2–3, 30 October 2008, Pages 257-263
نویسندگان
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