Abstract Developing a facile and green approach to synthesize gold nanoparticles (AuNPs) with high catalytic activities for the reduction of toxic nitrophenols to beneficial aminophenols is of tremendous environmental and industrial relevance. The present study reports an environmentally benign synthesis of AuNPs using aqueous extract of seaweed Lobophora variegata as a potential bioreductant. The signatory pinkish red color and a surface Plasmon resonance peak at 530 nm in the UV-Visible spectrum confirmed the formation of AuNPs. TEM images revealed that the biosynthesised AuNPs were spherical in shape with an average size of 11.69 + 2.38 nm. The high crystallinity of the biogenic AuNPs is confirmed from the clear lattice fringes in the High resolution TEM images, bright circular rings in SAED pattern and Bragg’s reflections of (111), (200), and (220) in XRD pattern. FTIR spectra revealed the role of bioactive metabolites in stabilizing the nanoparticles. The report emphasizes the spectroscopic investigation on the efficacy of the biosynthesized AuNPs as excellent catalyst in the reduction of anthropogenic organic pollutants, 4-nitrophenol (4NP), 3-nitrophenol (3NP), and 2-nitrophenol (2NP) to the corresponding aminophenols using NaBH4, which followed a pseudo-first-order kinetics with rate constants in the order k2NP > k4NP > k3NP.

中文翻译：

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利用海藻 Lobophora variegata 绿色合成金纳米粒子及其在还原硝基苯酚中的潜在应用

摘要 开发一种简便、绿色的方法来合成具有高催化活性的金纳米粒子 (AuNPs)，用于将有毒硝基酚还原为有益的氨基酚，具有巨大的环境和工业相关性。本研究报告了使用海藻 Lobophora variegata 的水提取物作为潜在生物还原剂的 AuNPs 的环境良性合成。紫外可见光谱中的标志性粉红色和 530 nm 处的表面等离子体共振峰证实了 AuNPs 的形成。TEM 图像显示生物合成的 AuNP 呈球形，平均尺寸为 11.69 + 2.38 nm。高分辨率 TEM 图像中清晰的晶格条纹、SAED 图案中的明亮圆环和 (111)、(200) 的布拉格反射证实了生物源 AuNP 的高结晶度，和 (220) 在 XRD 图中。FTIR 光谱揭示了生物活性代谢物在稳定纳米颗粒中的作用。该报告强调了对生物合成 AuNPs 作为极好的催化剂在减少人为有机污染物 4-硝基苯酚 (4NP)、3-硝基苯酚 (3NP) 和 2-硝基苯酚 (2NP) 为相应氨基苯酚方面的功效的光谱研究，使用NaBH4 遵循准一级动力学，速率常数为 k2NP > k4NP > k3NP。