Faculty of Chemistry and Chemical Technology, Al-Farabi Kazakh National University, Almaty 050040, Kazakhstan.
LLP Scientific Production Technical Center "Zhalyn", Almaty 050012, Kazakhstan.
Int J Mol Sci. 2023 Jul 11;24(14):11317. doi: 10.3390/ijms241411317.
This study presents the synthesis of zeolites derived from coal fly ash (CFA) using the fusion-assisted alkaline hydrothermal method. The zeolites were synthesized by combining CFA and NaOH at a molar ratio of 1:1.2 under fusion temperatures of 500, 600, and 700 °C. Subsequently, the obtained zeolites were subjected to further modifications through the incorporation of magnetic (FeO) and silver (Ag) nanoparticles (NPs). The FeO NPs were introduced through co-precipitation of Fe(NO) and FeCl at a molar ratio of 1:1, followed by thermal curing at 120 °C. On the other hand, the Ag NPs were incorporated via ion exchange of Na with Ag and subsequent reduction using NaBH. The synthesized porous materials exhibited the formation of zeolites, specifically analcime and sodalite, as confirmed by X-ray diffraction (XRD) analysis. Additionally, the presence of FeO and Ag NPs was also confirmed by XRD analysis. The elemental composition analysis of the synthesized nanocomposites further validated the successful formation of FeO and Ag NPs. Nitrogen porosimetric analysis revealed the formation of a microporous structure, with the BET surface area of the zeolites and nanocomposites ranging from 48.6 to 128.7 m/g and pore sizes ranging from 0.6 to 4.8 nm. The porosimetric characteristics of the zeolites exhibited noticeable changes after the modification process, which can be attributed to the impregnation of FeO and Ag NPs. The findings of this research demonstrate the effectiveness of the fusion-assisted method in producing synthetic zeolites and nanocomposites derived from CFA. The resulting composites were evaluated for their potential application in the removal of mercury ions from aqueous solutions. Among the samples tested, the composite containing Ag NPs exhibited the highest adsorption capacity, reaching 107.4 mg of Hg per gram of composite. The composites modified with FeO NPs and Ag/FeO nanocomposites displayed adsorption capacities of 68.4 mg/g and 71.4 mg/g, respectively.
本研究采用熔融辅助堿性水热法合成了源自粉煤灰（CFA）的沸石。将 CFA 和 NaOH 以摩尔比 1:1.2 混合，在 500、600 和 700°C 的熔融温度下合成沸石。随后，通过引入磁性（FeO）和银（Ag）纳米粒子（NPs）对所得沸石进行进一步修饰。通过摩尔比为 1:1 的 Fe(NO)和 FeCl 的共沉淀引入 FeO NPs，然后在 120°C 下进行热固化。另一方面，通过 Na 与 Ag 的离子交换和随后使用 NaBH 还原引入 Ag NPs。合成的多孔材料通过 X 射线衍射（XRD）分析证实了沸石的形成，特别是方沸石和钠沸石。此外，XRD 分析还证实了 FeO 和 Ag NPs 的存在。合成纳米复合材料的元素组成分析进一步验证了 FeO 和 Ag NPs 的成功形成。氮孔隙率分析揭示了微孔结构的形成，沸石和纳米复合材料的 BET 表面积范围为 48.6 至 128.7 m²/g，孔径范围为 0.6 至 4.8nm。沸石的比孔容特性在修饰过程后发生了明显变化，这可归因于 FeO 和 Ag NPs 的浸渍。该研究结果表明，熔融辅助法在从粉煤灰生产合成沸石和纳米复合材料方面具有有效性。评估了所得复合材料在从水溶液中去除汞离子方面的潜在应用。在所测试的样品中，含有 Ag NPs 的复合材料表现出最高的吸附容量，达到每克复合材料 107.4mg 的汞。用 FeO NPs 修饰的复合材料和 FeO/Ag 纳米复合材料的吸附容量分别为 68.4mg/g 和 71.4mg/g。
