Hierarchical superstructures of Ag nanoparticles with novel morphology resembling multiple growth hillocks were synthesized for the first time using photochemical method through the screw-dislocation-driven, nanoparticle-mediated crystal growth mechanism. The Ag nanoparticles were in situ synthesized from the photoreduction of Ag + ions adsorbed on ZnO. The absence of organic capping agents in the synthesis protocol makes this photochemical approach suitable for preparing metal/semiconductor hybrid materials with clean metal/semiconductor interfaces that can find important applications in plasmon-assisted photocatalysis, photovoltaics, and plasmon-enhanced spectroscopies. Finally, we demonstrated that the photoluminescence properties of ZnO can be subtly modified by the photodeposited Ag nanostructures through synergistic mechanisms of surface plasmon−exciton resonant coupling and surface passivation.

Two types of out-of-substrate Ag–Ag 2 O nanoplates were grown on a ZnO substrate through a surfactantless photochemical method. First, the in situ photochemically synthesized Ag–Ag 2 O nanoparticles further crystallized into nanoplate-like superstructures with rough surfaces and ragged edges. The nanoparticle-mediated crystallization process was governed by a layer-by-layer crystallization mechanism. Our study should help fundamentally understand the formation mechanism of hierarchical nanoparticle superstructures. Under continuous UV illumination, the hundreds of nanometer-sized rough nanoplates (i.e., the nanoplate-like superstructures of nanoparticles) can be transformed into large smooth nanoplates with sizes of up to several micrometers. The out-of-substrate Ag–Ag 2 O nanoplates/ZnO heterostructures are potentially promising for photocatalytic applications.