Silver nanoparticles stabilized by bundled tungsten oxide nanowires with catalytic and antibacterial activities

An in situ redox reaction was developed to synthesize bundled tungsten oxide (WO3@W18O49) ultrafine nanowires (BUNs) loaded with Ag nanoparticles using weakly reductive W18O49 and oxidative silver nitrate as precursor. However, due to the weak activation between the two reactants, redox just happened on the surface of W18O49, resulting in the formation of W18O49 coated with WO3 (here, we refer this structure to WO x simply), and the bulk phase of the composites retained the same pattern. Ag nanoparticles (<5 nm) with a narrow size distribution were obtained and immobilized onto WO x BUNs without any aggregation. The paper presented a systematic investigation on the Ag-WO x nanocomposite used as a catalyst for the reduction of p-nitrophenol and as an antibacterial agent against Escherichia coli. The remarkably enhanced performance may be ascribed to the moderate interaction of the small Ag-NPs and WO x BUNs with high specific surface area.