We prepared silver nanoparticles (AgNP) embedded in SiO₂ using a green polyol approach by conducting the synthesis at ambient temperature and pH. Glycerol solutions of SiO₂ and silver nitrate were stirred overnight at room temperature. UV-vis spectra and TEM images of the reaction dispersion and XRD patterns of the centrifuged solid confirmed formation of AgNP (6 ± 2 nm) were embedded in SiO₂. AAS showed that, about 50% of initial silver was deposited on SiO₂. The presence of SiO₂ enhanced the formation of AgNP and the stability of Ag/SiO₂ in glycerol. The reason for these findings was probably the ultrasonic-probe dispersion of SiO₂ in glycerol, which caused chemical interactions between glycerol and SiO₂. Compared to bare AgNP, the AgNP/SiO₂ demonstrated higher catalytic activity toward 4-nitrophenol reduction by NaBH₄. The highest apparent rate constant was approximately 1.1 ∗ 10⁻⁴ s⁻¹, comparable with Ag/SiO₂ catalysts prepared using other methods. This study proposes a greener polyol method to synthesize SiO₂-supported AgNP catalyst that does not require heating or regulating pH of the reaction mixture. This nanocomposite can be used in catalytic, antimicrobial, sensing, and other applications that are using AgNP/SiO₂ synthesized by conventional methods.

中文翻译：

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室温多元醇合成Ag / SiO2纳米复合材料作为4-硝基苯酚还原催化剂

我们通过在环境温度和pH下进行合成，使用绿色多元醇方法制备了嵌入SiO _2的银纳米颗粒（AgNP）。将SiO ₂和硝酸银的甘油溶液在室温下搅拌过夜。反应分散液的紫外可见光谱和TEM图像以及经离心分离的固体的XRD图谱证实了在₂ SiO ₂中嵌入了AgNP（6±2 nm）的形成。AAS表明，约50％的初始银沉积在SiO _2上。SiO ₂的存在增强了甘油中AgNP的形成和Ag / SiO ₂的稳定性。这些发现的原因可能是SiO ₂的超声探头分散在甘油中，导致甘油和SiO ₂之间的化学相互作用。与裸AgNP相比，AgNP / SiO ₂对NaBH ₄还原4-硝基苯酚具有更高的催化活性。最高表观速率常数约为1.1 * 10 ^-4  s ^-1，与使用其他方法制备的Ag / SiO ₂催化剂相当。这项研究提出了一种绿色环保的多元醇方法来合成SiO ₂负载的AgNP催化剂，该方法不需要加热或调节反应混合物的pH。该纳米复合材料可用于催化，抗菌，传感以及使用通过常规方法合成的AgNP / SiO _2的其他应用。