Hierarchical Au-CuO nanocomposite from redox transformation reaction for surface enhanced Raman scattering and clock reaction

作者：Pal Jaya^*; Ganguly Mainak; Dutta Soumen; Mondal Chanchal; Negishi Yuichi; Pal Tarasankar

来源：CrystEngComm, 2014, 16(5): 883-893.

DOI：10.1039/c3ce41766b

Electrochemical processing has already manifested its prominence for obtaining well structured composite materials. The method is highly precise and is reduction potential driven. This methodology has resulted in a hierarchical Au-CuO nanocomposite from a chosen redox transformation reaction between the newly synthesized spherical and roughened Cu2O nanoparticles and HAuCl4. Thus the attractive shape as well as reducing capability of Cu2O made it promising as a starting material. The proposed redox transformation reaction does not need any additional reducing or stabilizing agents. The reduction potential value of CuO/Cu2O (+0.66 V vs. SHE) supports the quantitative reduction of Au(III) ions because of its higher reduction potential (+1.69 V vs. SHE) i.e., for the AuCl4-/Au half cell. The prescribed conditions, spontaneous redox reaction and the morphology of Cu2O nanoparticles help to produce the unique Au-CuO nanoflowers. The formation of Au-CuO nanocomposites from Cu2O nanospheres is characterised by several physical techniques such as XRD, XPS and FTIR. Finally the flower like Au-CuO nanocomposite shows higher SERS activity with 4-aminothiophenol (4-ATP) as a probe molecule than what is evident from the individual components (Au or Cu2O or CuO). Additionally the derived Au-CuO nanocomposite has also been found to be an effective catalyst for the clock reaction employing methylene blue and ascorbic acid in solution.

• 出版日期2014