Synthesis of Cu/CuO nanoparticles in mesoporous material by solid state reaction

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• 作者：Sh. Sohrabnezhad ; A. Valipour
• 关键词：Plasmon resonance ; Copper clusters ; Diffuse reflectance spectroscopy ; Solid state reaction ; Cu/MCM-41
• 刊名：Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
• 出版年：2013
• 出版时间：October, 2013
• 年：2013
• 卷：114
• 期：Complete
• 页码：298-302
• 全文大小：1121 K

文摘

The Mobil Composition of Matter No. 41 (MCM-41) containing 1.0 and 5.0 wt. % of Cu was synthesized under solid state reaction. The calcinations of samples were done at two different temperatures, 500 and 300 ¡ãC. X-ray diffraction (XRD), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM) were used for samples characterization. Powder X-ray diffraction showed that when Cu(CH₃COO)₂ content is about 1.0 wt. % in Cu/MCM-41, the guest CuO-NPs and copper ions is formed on the silica channel wall, and more exists in the crystalline state. When Cu(CH₃COO)₂ content exceeds this value (5.0 wt. % ), CuO nanoparticles and Cu²⁺ ions can be observed in low crystalline state. From the diffuse reflectance spectra it was confirmed that 5 wt. % Cu/MCM-41 sample calcined at 500 ¡ãC show plasmon resonance band due to Cu nanoparticles in the range between 500 and 600 nm and small copper clusters Cu_n in 450 nm. It also shows that some of the Cu²⁺ ions are present octahedrally in extraframework position in all samples. Both fourier transform infrared and diffuse reflectance spectra indicate that some of Cu²⁺ ions are tetrahedrally within the framework position in 1 wt. % Cu/MCM-41 samples. TEM images indicated that nanoparticles size of CuO is in range of 30-40 nm.