We report a synthesis method that made use of a dual-glycol system, allowing discrete and size-tunable Cu nanoparticles to be deposited onto ZnO nanorods. Successful reduction of Cu was demonstrated by the distinct plasmon absorption, and we report for the first time a clear linear correlation of Cu plasmon peak position shifts with the variation of Cu particle sizes. Stable and discrete Cu nanoparticles were obtained despite deliberately leaving out conventional polymeric protecting agents such as poly-(vinylpyrrolidone). The synthesized material exhibited robustness in ethanol steam reforming that occurred at high reaction temperature of up to 600 °C. Analysis of absorption spectra revealed the relative attenuation of ZnO absorption with increasing amount of Cu nanoparticles deposited, confirming clear electronic interaction between the coupled metallic and oxide components.

Silver nanoparticles (AgNPs) are widely sought after for a variety of biomedical and environmental applications due to their antimicrobial and catalytic properties. We present here a green and simple synthesis of AgNPs utilizing traditional Chinese medicinal herbs. The screening of 20 aqueous herb extracts shows that Sheng Di Huang (Rehmannia glutinosa) had the most promising potential in producing AgNPs of 30±6 nm, with narrow size distribution and high crystallinity. The antimicrobial activities of these AgNPs conducted on E. coli cells were found to be superior in comparison to poly(vinylpyrrolidone)‐capped AgNPs synthesized using common chemical method. Additionally, the AgNPs obtained possess excellent catalytic performance in the reduction of 4‐nitrophenol to 4‐aminophenol. We compared the phytochemical and FTIR spectral analyses of the herb extract before and after synthesis, in order to elucidate the phytochemicals responsible for the reduction of Ag+ ions and the capping of the AgNPs produced.

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