Abstract Biogenic synthesis of noble metal nanoparticles is particularly interested due to the effective applications for plasmonic catalysis and bioactivity. In this work, aqueous extract of waste Nypa fruticans (NF) fruit husk was utilized to synthesize silver nanoparticles (NF-AgNPs) and gold nanoparticles (NF-AuNPs). The effected parameters on the green reduction of metallic nanoparticles (MNPs) were investigated. Under optimum conditions of concentration, temperature and time, the biosynthesized NF-AgNPs and NF-AuNPs showed spherical nanoparticles with average size of 10–15 nm and 15–20 nm, respectively. The presence of AgCl in NF-AgNPs has been demonstrated by X-ray diffraction analysis. The elemental components of all samples confirmed the presence of anions and cations come from the aqueous extract. The biosynthesized nanoparticles were evaluated bacterial activity against three bacterial strains. NF-AgNPs exhibited selective antibacterial activity against Bacillus cereus but no activity against Staphylococcus aureus and Salmonella typhimurium at all tested concentrations. The recyclable catalysis activity of the biosynthesized nanoparticles was evaluated for the reduction of nitrophenols in the presence of sodium borohydride which possessed good catalytic performance in six running numbers. Additionally, AgCl played role as a source supplying AgNPs has been demonstrated in catalytic reduction of p-nitrophenol. For study of catalytic kinetic, NF-AgNPs possessed higher rate constant in comparison with NF-AuNPs whereas TOF values of NF-AuNPs was determined to be higher than those of NF-AgNPs.

中文翻译：

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来自 Nypa fruticans 果壳废料的贵金属纳米粒子：生物合成、表征、抗菌活性和可回收催化

摘要 由于等离子催化和生物活性的有效应用，贵金属纳米粒子的生物合成特别令人感兴趣。在这项工作中，利用废猞猁 (NF) 果壳的水提取物合成银纳米粒子 (NF-AgNPs) 和金纳米粒子 (NF-AuNPs)。研究了对金属纳米粒子 (MNP) 绿色还原的影响参数。在最佳浓度、温度和时间条件下，生物合成的 NF-AgNPs 和 NF-AuNPs 显示出平均尺寸分​​别为 10-15 nm 和 15-20 nm 的球形纳米颗粒。X 射线衍射分析证明了 NF-AgNPs 中存在 AgCl。所有样品的元素成分都证实存在来自水提取物的阴离子和阳离子。评估了生物合成的纳米颗粒对三种细菌菌株的细菌活性。在所有测试浓度下，NF-AgNPs 对蜡样芽孢杆菌表现出选择性抗菌活性，但对金黄色葡萄球菌和鼠伤寒沙门氏菌没有活性。在硼氢化钠存在下评估了生物合成纳米颗粒的可回收催化活性，用于还原硝基苯酚，硼氢化钠在六个运行数中具有良好的催化性能。此外，在对硝基苯酚的催化还原中，AgCl 作为 AgNPs 的来源已被证明。对于催化动力学的研究，与 NF-AuNPs 相比，NF-AgNPs 具有更高的速率常数，而 NF-AuNPs 的 TOF 值被确定为高于 NF-AgNPs。