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[摘要]：We report a simple and efficient method of preparing gold nanoparticles (AuNPs) using the eco-compatible inorganic material layered double hydroxide (LDH) under mild conditions. In an aqueous solution, acrylate ions, which is used to modify LDH, serves the dual function of facilitating the exfoliation of stacked LDH layers to provide positively charged nanosheets (1 nm thick x 70-200 nm diameter) and acting as a reducing agent. In situ reduction of NaAuCl4 using the acrylate ions-exfoliated LDH dispersion as a reaction medium gives rise to the formation of AuNPs on the surface of the LDH nanosheets due to electrostatic interactions between the LDH support and the negatively charged Au species. Transmission electron micrographs confirm the formation of well-defined AuNPs with typical sizes of 10-20 nm. At high Au concentrations, random gold nanowires are obtained, the formation of which is attributed to concentration-induced assembly of AuNPs. The mechanisms underlying the formation and the morphology of the AuNPs are explored by varying the concentrations of LDH and gold species and the solution pH, and by utilizing elevated temperature. The potential application of the prepared AuNP-LDH hybrid material for interesting catalytic properties is also demonstrated. |
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