Metal nanostructures have attracted attention in the field of nanoscience and nanotechnology because of their unique properties and potential applications in catalysis, electronic and optical nanodevices.1,2 Therefore, selective synthesis of such nanomaterials with well-defined size remains a scientific challenge. One of most promising methods of preparing metal nanoparticles is the template synthesis, in which porous materials with uniform void spaces are used as a host to occlude the nanoparticles as a guest. Mesoporous silicas such as MCM-41, SBS-15 and FSM-16 have a great opportunity as a support of nanostructured metal due to their large pores (2-50 nm) with a narrow distribution and a high surface area (up to 1000m2/g). We report on a novel and facile method to encapsulate uniformly and highly dispersed Au nanoparticles/wires in mesoporous structures by in-situ oxidation-reduction between HAuCl4 and aniline group in anilinepropyl-functionalized MCM-41. The advantage of our method is that the synthesis procedure is simply because the introduction of AuCl4- ion into the mesoporous matrix and the oxidation-reduction reaction take place simultaneously, and the reaction condition is mild due to its relatively low temperature and solution-based reaction. The proposed method can also be extended to prepare other metals or metal compound nanoparticles.

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