Silver nanoparticles were formed electrochemically in the presence of poly( N -vinylpyrrolidone) (PVP) to generate highly stable nanoparticles with a mean diameter of 12 nm. The optimised conditions involved formation at − 6.0 V vs Ag|Ag + with a PVP:Ag + ratio of 75:1. Particle agglomeration was observed when the PVP:Ag + ratio was reduced to 25:1 and when extended polarisation periods were employed. Using the optimised conditions, the silver nanoparticles remained stable for periods in excess of 2 months. The nanoparticles were immobilised inside a polyacrylamide hydrogel and used for the reduction of 4-nitrophenol. The rate constant obtained for the reduction of 4-nitrophenol was calculated as 7.1 × 10 −4 to 1.6 × 10 −3 s −1 depending on the amount of silver. The hydrogel–Ag composite was stable and could be stored for several months, while there was little change in the rate constant when it was repeatedly used.

中文翻译：

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银纳米粒子的电化学形成及其固定在水凝胶基质中的催化活性

在聚（N-乙烯基吡咯烷酮）（PVP）存在下电化学形成银纳米颗粒，以产生平均直径为 12 nm 的高度稳定的纳米颗粒。优化条件包括在 - 6.0 V vs Ag|Ag + 下形成，PVP:Ag + 比率为 75:1。当 PVP:Ag + 比率降低到 25:1 并且使用延长的极化周期时，观察到颗粒团聚。使用优化的条件，银纳米粒子在超过 2 个月的时间内保持稳定。纳米颗粒固定在聚丙烯酰胺水凝胶内，用于还原 4-硝基苯酚。根据银的量，4-硝基苯酚的还原速率常数计算为7.1×10 -4 至1.6×10 -3 s -1 。水凝胶-银复合材料稳定，可以储存几个月，