Abstract

In this paper, the preparation of silk fibroin (SF) and silk fibroin-gold nanoparticles (SF-AuNPs) nanocomposites (NC) and their adsorbability of methylene blue (MB) dye is reported. SF is used in this work as a template to reduce gold salt (HAuCl₄.H₂O) into AuNPs. The optical absorption displays the AuNPs in SF by showing a band at λ = 540 nm. The X-ray diffraction (XRD) and the transmission electron microscopy (TEM) study reveal the crystalline nature of the AuNPs. The TEM image indicates that the AuNPs are mostly spherical in shape with an average diameter of around 6.22 ± 1.28 nm. The scanning electron microscopy (SEM) and micrograph shows the AuNPs as uniformly dispersed in the SF. The samples are evaluated as novel adsorbents, and influencing factors like solution pH, contact time, and kinetic models are investigated. The adsorption kinetics validates the practicality of the pseudo-second-order kinetics by best linear fit (R²=0.987 for SF film) and (R²=0.989 for SF-AuNPs NC film). The Langmuir and Freundlich isothermal models used in the study, maximum adsorption capacity for the dye is estimated to be 263.15 mg g⁻¹ (SF) and 313.47 mg g⁻¹ (SF-AuNPs). The decolorization percentage is about 95.62% (SF) and 98.66% (SF-AuNPs). The recycle tests demonstrate that the samples can be reused four times with removal efficiency of more than 80%. The results suggest that the SF and SF-AuNPs films can be used as efficient sorbents for MB dye removal from a solution.

摘要

本文报道了丝素蛋白 (SF) 和丝素蛋白-金纳米粒子 (SF-AuNPs) 纳米复合材料 (NC) 的制备及其对亚甲基蓝 (MB) 染料的吸附性。在这项工作中使用 SF 作为模板来减少金盐 (HAuCl ₄ .H ₂O) 成金纳米粒子。光学吸收通过在 λ = 540 nm 处显示一条带来显示 SF 中的 AuNP。X 射线衍射 (XRD) 和透射电子显微镜 (TEM) 研究揭示了 AuNPs 的结晶性质。TEM 图像表明，AuNPs 大多呈球形，平均直径约为 6.22 ± 1.28 nm。扫描电子显微镜 (SEM) 和显微照片显示 AuNPs 均匀分散在 SF 中。样品被评估为新型吸附剂，并研究了溶液 pH 值、接触时间和动力学模型等影响因素。吸附动力学通过最佳线性拟合（SF 薄膜的R ² =0.987）和（R ² ）验证了准二级动力学的实用性= 0.989 对于 SF-AuNPs NC 薄膜）。研究中使用的 Langmuir 和 Freundlich 等温模型，染料的最大吸附容量估计为 263.15 mg g ^-1 (SF) 和 313.47 mg g ^-1 (SF-AuNPs)。脱色率约为 95.62% (SF) 和 98.66% (SF-AuNPs)。回收测试表明，样品可以重复使用四次，去除效率超过80%。结果表明，SF 和 SF-AuNPs 薄膜可用作从溶液中去除 MB 染料的有效吸附剂。