Autocatalytic-assembly based on self-decomposing templates: a facile approach toward hollow metal nanostructures

Hollow metal nanostructures have received increasing interest because they exhibit unique chemical and physical properties different from their solid counterparts. In this work, the autocatalytic-reduction approach based on the self-decomposing of metal hydroxides and oxides is reported, which is distinct from the traditional template methods. Under solution conditions of a reducing atmosphere, metal hydroxides can serve as both the autocatalytic reagent and the sacrificial templates in the reaction process. It is demonstrated that the autocatalytic-reduction method is a general approach to fabricate a series of metal hollow structures, including hollow Ni nanospheres (NSs), Ni nanotubes (NTs), bead-like Ni NSs, and hollow Cu microspheres. Moreover, the structural diversity of original M(OH)(x) or MOx/2 (M = metal) templates allows the preparation of size and shape-adjustable templates. A possible mechanism for hollow structure formation is also proposed.