Au–ZnO hybrid nanoflowers, nanomultipods and nanopyramids: one-pot reaction synthesis and photocatalytic properties

Abstract

The preparation of noble metal-semiconductor hybrid nanocrystals with controlled morphologies has received intensive interest in recent years. In this study, facile one-pot reactions have been developed for the synthesis of Au-ZnO hybrid nanocrystals with different interesting morphologies, including petal-like and urchin-like nanoflowers, nanomultipods and nanopyramids. In the synthesis strategy, oleylamine-containing solution serves as the reaction medium, and the in situ generated Au seeds play an important role in the subsequently induced growth of ZnO nanocrystals. With the aid of several surfactants, hybrid nanocrystals with different morphologies that have considerable influences on their optical and photocatalytic activities are readily achieved. Through high-resolution transmission electron microscopy measurements, an observed common orientation relationship between ZnO and Au is that ZnO nanocrystals prefer to grow with their polar {001} facets on the {111} facets of Au nanocrystals, and well-defined interfaces are evident. Surface plasmon resonance bands of Au with different positions are observed in the UV-vis spectra, and the UV and visible emissions of ZnO are found to be dramatically reduced. Finally, the as-prepared Au-ZnO nanocrystals exhibit excellent photocatalytic activity for the photodegradation of rhodamine B compared with pure ZnO nanocrystals. The Au-ZnO hybrid nanopyramids show the highest catalytic efficiency, which is correlated with the exposed crystal facets, crystallinity and the formation of hybrid nanostructures. The as-prepared Au-ZnO hybrid nanocrystals are expected to find diverse potential applications in the fields such as photocatalysis, solar energy conversion, sensing and biological detection.

Preparation of flower-like ZnO architectures assembled with nanosheets for enhanced photocatalytic activity

“…TEM images reveals that plenty of voids and interspaces present among the nanosheets of both flower-like ZnO products ( Fig. 1c and f), which could provide abundant spaces and facilitate the rapid diffusion of reaction molecules, thus improving their performances as catalyst or sensor materials [28][29][30][31].…”

Enhanced current efficiency of organic light-emitting devices due to a broad localized surface plasmonic resonance of Au–ZnO nanocomposites

“…1(a) [23]. The diffraction peaks of 2Â at 38.3 • is related to the (1 1 1) planes of the cubic Au NPs in the Au-ZnO NCs films [24], indicating that the Au NPs are embedded in the ZnO NPs.…”

Controlled preparation of hollow SnO2@M (M = Au, Ag) heterostructures through template-assist method for enhanced photocatalysis

“…Metal-semiconductor hybrid NPs may retain the properties of individual components and further enhanced properties (such as optical, electrical and catalytic property) and even present new synergistic effect [4]. These new properties may generate from the interface of noble metals and semiconductors essentially [5,6].…”