Institute for Polymers, Composites and Biomaterials of National Research Council (IPCB-CNR), P.le Enrico Fermi 1, 80055 Portici, Italy.
Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin, Italy.
Molecules. 2022 Mar 17;27(6):1944. doi: 10.3390/molecules27061944.
Hybrid tannic acid-silica-based porous nanoparticles, TA-SiO NPs, have been synthesized under mild conditions in the presence of green and renewable tannic acid biopolymer, a glycoside polymer of gallic acid present in a large part of plants. Tannic acid (TA) was exploited as both a structuring directing agent and green chelating site for heavy metal ions recovery from aqueous solutions. Particles morphologies and porosity were easily tuned by varying the TA initial amount. The sample produced with the largest TA amount showed a specific surface area an order of magnitude larger than silica nanoparticles. The adsorption performance was investigated by using TA-SiO NPs as adsorbents for copper (II) ions from an aqueous solution. The effects of the initial Cu ions concentration and the pH values on the adsorption capability were also investigated. The resulting TA-SiO NPs exhibited a different adsorption behaviour towards Cu, which was demonstrated through different tests. The largest adsorption (i.e., ~50 wt% of the initial Cu amount) was obtained with the more porous nanoplatforms bearing a higher final TA content. The TA-nanoplatforms, stable in pH value around neutral conditions, can be easily produced and their use would well comply with a green strategy to reduce wastewater pollution.
单宁酸-硅基多孔纳米粒子（TA-SiO NPs）在温和条件下合成，其中使用了绿色可再生的单宁酸生物聚合物，这是一种存在于大部分植物中的没食子酸糖苷聚合物。单宁酸（TA）既可以作为结构导向剂，也可以作为绿色螯合位点，用于从水溶液中回收重金属离子。通过改变 TA 的初始用量，很容易调整粒子的形态和孔隙率。用 TA 量最大的样品制备的比表面积比二氧化硅纳米粒子大一个数量级。通过使用 TA-SiO NPs 作为吸附剂从水溶液中吸附铜（II）离子，研究了吸附性能。还研究了初始 Cu 离子浓度和 pH 值对吸附能力的影响。结果表明，TA-SiO NPs 对 Cu 表现出不同的吸附行为，这通过不同的测试得到了证明。在具有更高最终 TA 含量的多孔纳米平台上，得到了最大的吸附量（即约 50wt%的初始 Cu 量）。在接近中性 pH 值的条件下稳定的 TA-纳米平台易于制备，其使用符合减少废水污染的绿色策略。
