de Carvalho Maíra Vasconcelos, Lago João Henrique G, Hajjar-Garreau Samar, Camilo Fernanda F, Oliveira Larissa V F
Chemistry Department, Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of São Paulo, SP-09913-030 Diadema, Brazil.
Center of Natural Sciences and Humanities, Federal University of ABC, SP-09210-580 Santo Andre, Brazil.
ACS Omega. 2025 Apr 7;10(15):14805-14815. doi: 10.1021/acsomega.4c09636. eCollection 2025 Apr 22.
Bimetallic nanoparticles (BNPs) have attracted much attention recently due to their improved properties compared to monometallic ones. Gold and silver nanoparticles (AuAgNPs) are among the most studied BNPs. Using these particles as powder or dispersion has drawbacks such as ease of aggregation and difficulty separating and recovering from the reaction medium. Therefore, immobilizing these nanoparticles in polymeric matrices, such as cellulose, is appealing. In this context, the present work focused on preparing unmodified cellulose membranes containing AuAgNPs for use as heterogeneous catalysts in reducing the pollutant 4-nitrophenol. Incorporating these nanoparticles into cellulose membranes represents a significant advancement in heterogeneous catalysis. In addition to being eco-friendly, cellulose membranes offer ease of handling and the potential for reusability, which are crucial factors in catalysis. The nanoparticles were prepared in an aqueous medium from the seeded growth of a silver shell around AuNP seeds. Images recorded by transmission electron microscopy showed that the particles have diameters smaller than 100 nm and are core-shell type. The cellulose membrane was prepared by dissolving microcrystalline cellulose in an ionic liquid, followed by a regeneration process using water. Next, the bimetallic nanoparticles were incorporated into the cellulose membrane. The analyses revealed that the membranes contain bimetallic nanoparticles homogeneously distributed in the matrix, and the inductively coupled plasma-optical emission spectroscopy (ICP-OES) showed that the membrane has 0.339 wt % in silver and 0.069% in gold. The membranes produced were efficient heterogeneous catalysts in reducing 4-nitrophenol, used for at least four cycles without loss of efficiency. This material can be easily isolated from the reaction medium, avoiding centrifugation or filtration processes for reuse. This study represents the first use of AuAgNPs supported on nonmodified cellulose membranes as heterogeneous catalysts, marking an advancement in catalysis and material science.
双金属纳米颗粒（BNPs）由于其相较于单金属纳米颗粒具有改进的性能，近年来备受关注。金和银纳米颗粒（AuAgNPs）是研究最多的双金属纳米颗粒之一。将这些颗粒用作粉末或分散体存在诸如易于聚集以及难以从反应介质中分离和回收等缺点。因此，将这些纳米颗粒固定在聚合物基质（如纤维素）中很有吸引力。在此背景下，本工作聚焦于制备含有AuAgNPs的未改性纤维素膜，用作还原污染物4-硝基苯酚的多相催化剂。将这些纳米颗粒掺入纤维素膜代表了多相催化领域的一项重大进展。除了环保外，纤维素膜易于处理且具有可重复使用的潜力，这些都是催化过程中的关键因素。纳米颗粒是在水介质中通过在AuNP种子周围生长银壳的种子生长法制备的。透射电子显微镜记录的图像显示，这些颗粒的直径小于100 nm，且为核壳型。纤维素膜是通过将微晶纤维素溶解在离子液体中，然后用水进行再生过程制备的。接下来，将双金属纳米颗粒掺入纤维素膜中。分析表明，膜中含有均匀分布在基质中的双金属纳米颗粒，电感耦合等离子体发射光谱（ICP-OES）显示该膜中银的含量为0.339 wt%，金的含量为0.069%。所制备的膜在还原4-硝基苯酚方面是高效的多相催化剂，可使用至少四个循环而不损失效率。这种材料可以很容易地从反应介质中分离出来，避免了离心或过滤过程以便重复使用。本研究代表了首次将负载在未改性纤维素膜上的AuAgNPs用作多相催化剂，标志着催化和材料科学领域的一项进展。
Int J Mol Sci. 2024-3-13
Adv Colloid Interface Sci. 2020-4-16
Nanomaterials (Basel). 2019-6-28
Zotero 插件
